Common ESL Writing Errors

ESL writers sometimes mix up the definite and indefinite articles. But each of these has a specific use, so using the wrong one can create problems. Remember:

• We use the definite article (the) when we know the specific identity of a noun. This could be because it is unique (e.g., the President of the USA), a superlative (e.g., the tallest man), or because its identity is clear from the context (e.g., if I say I am going to “walk the dog,” you can guess I have a specific dog in mind).

Using the wrong article type won’t necessarily make your writing ungrammatical, but it can change the meaning of what you say. For example:

As such, you should be careful about article choice when writing. And, in general, if you are definite about the identity of the noun, you will need the definite article (i.e., “the”).

If you are using a concrete, singular countable noun or a superlative, it will need an article or another determiner before it. Leaving out the article will be ungrammatical:

However, you should use a noun without an article in some cases. This is sometimes known as the zero article, and we’ll look at where it applies in the following sections.

You do not need an article with plural, uncountable, or abstract nouns when making generalizations or referring to a whole class of things, such as in the following:

Here, using articles in the first sentences makes them too specific. “The cars” implies that we’re talking about a specific group of cars rather than cars in general. And “the happiness” is simply wrong, since “happiness” is an abstract, indivisible concept. As such, we’ve removed the articles in the second set of sentences to make them grammatical.

We do not typically use articles before proper nouns, including the names of people, countries, languages, places, months, individual landmarks, etc.

There are some exceptions to this, such as when referring to:

• A specific day (e.g., We went out the Friday before last)
• A group of places (e.g., We live in the United States)
• A place with an article in its name (e.g., the Eiffel Tower, the Matterhorn)

However, the zero article will be correct for most proper nouns.

In some cases, we can use singular countable nouns in a general sense without an article. Common examples of this include meals, substances, games, and places:

These are all correct! The key is that the noun is used to refer to a general concept in each case (e.g., we are referring to gold in general, not a specific piece of gold). We can use articles with these words sometimes, too, but only if referring to something specific.

For instance, if we said “We had a great dinner at that restaurant,” using “a” would show that we’re referring to one specific dinner, not the general concept of dinner.

Another very common error we see in ESL writing is mixing up “a” and “an.” These are both indefinite articles, so they play the same grammatical role. But the correct term to use in any given sentence will depend on the pronunciation of the noun that follows:

• If it starts with a consonant sound, use “a” (e.g., a puppy).
• If it begins with a vowel sound, use “an” (e.g., an egg).

Keep in mind that this applies to the sound of the word, not the letter itself. As such, you should use “a” with words like “university” or “European” as they start with a “y” sound. And you should use “an” with “hour” and “honor” as the “h” at the start of these words is silent.

As mentioned, articles are a type of determiner. Possessive pronouns (e.g., my, your, his, her, its, our, their) are also determiners, telling us who a noun belongs to. These words thus play a similar grammatical role to articles, so you do not need both:

Here, for instance, “my” and “the” both modify “glasses.” But since “my” already suggests specificity (i.e., they are my glasses, not just any glasses), we don’t need “the.”

An intransitive verb is a verb that does not need an object (i.e., the thing to which an action happens) to make sense. As such, if you try to add a noun or noun phrase after an intransitive verb as an object, the sentence will be ungrammatical. The verb “spoke,” for instance, is intransitive, so the following is incorrect:

If we wanted to show the relationship between “I spoke” and “my brother” here, we would need a preposition to link the intransitive verb to its object:

Here, for instance, the preposition “to” shows us the speaker and their brother have spoken. It can therefore help to check whether a verb is transitive or intransitive, as this will tell you whether or not the sentence needs an object.

We can also flip the issue above and focus on transitive verbs. These always take a direct object, so you do not need a preposition between verb and object:

Here, for instance, the transitive verb “discussed” is followed by the noun phrase “the weather” (i.e., the subject of the discussion). This is completely grammatical as it is. However, some ESL writers will add a preposition after an intransitive verb:

This is not necessary or grammatical. It results from treating a transitive verb as if it were intransitive. As above, then, if you’re not sure whether to use a prepositional phrase after a verb, it can help to check whether the verb is transitive or intransitive. Remember:

• Transitive verb = No preposition required between verb and object.

• Intransitive verb = Needs a preposition between verb and object.

There are a lot of prepositions in English and most of them have more than one meaning. As such, we won’t try to define them all here. But we will look at how preposition choice can affect the meaning of a sentence, followed by a range of commonly confused prepositions.

In terms of how preposition choice affects the meaning of a sentence, we can show this by returning to one of the examples above that used the preposition “to”:

The “to” here shows that the speaker is having a discussion with their brother. But if we use a different preposition in the same place, the relationship changes:

Here, the preposition “about” indicates that “my brother” is the subject of the discussion: i.e., the person the speaker is talking about, not the person to whom they are speaking. So while both sentences are grammatical, they are very different in meaning.

As such, you need to make sure not just that a sentence contains a preposition when it needs one, but that you use the right prepositions in the right places! We’ll now take a look at a few examples of commonly confused prepositions to help you do this.

With “in” and “at,” the correct term may depend on the time of day! For example, in English we typically use “in the” with “morning,” “afternoon,” and “evening”:

But we usually use “at” when talking about the night:

You could go for a run “in the night,” but that sounds like something a sporty vampire would do. So make sure to use “at” with “night” in your writing.

You can use the preposition “to” to discuss journeys (e.g., “I’m going to Tasmania”). But with the word “arrive,” we use “in” or “at” to describe reaching a destination. For instance:

Whether to use “in” or “at” typically depends on the destination:

• Use “in” for cities, countries, or other large areas.
• Use “at” for specific places (e.g., a library, a bar, or someone’s house).

Make sure to consider the destination when picking a preposition to go with “arrive.”

When referring to a time or date, we use different prepositions depending on the situation. If you’re talking about a time of day, for instance, the correct term is “at”:

For a specific day or date, we use “on”:

And for a month or year, the correct preposition is “in”:

In other words, the preposition depends on the time window in question.

It’s common to see “of” used alongside helper verbs like “should” or “must.” For example:

However, the correct word here isn’t even a preposition. It should be the verb “have,” which sounds a bit like “of” when spoken (hence the confusion). Thus, it should say:

So if you find yourself using “of” after a helper verb, the correct word will usually be “have”.

When talking about how long something has been happening, we use “for” when referring to a length of time (e.g., a period of hours, days, or months):

But if we’re using a specific time as a point of reference, we use “since”:

The difference here is that the first sentence refers to a measure of time, while the second refers to a fixed point in the past when the activity began.

We can use the prepositions “in” and “on” to describe the medium via which we see or hear something. However, we tend to use “in” only with print media:

And we use “on” when referring to broadcast or digital media:

As such, make sure to pick the preposition that matches the media you’re discussing.

This is not a complete list of preposition errors! Hopefully, though, it has given you a sense of how prepositions work and what to look for in your own writing. And don’t forget to ask a native speaker or a proofreader if you’re unsure about your preposition choices.

The basic word order in English is captured in the initials SVO:

Subject + Verb + Object

Each of these plays a specific role in the sentence:

• Subject (S) – The person or thing that enacts the verb in the sentence.
• Verb (V) – The action or state of being described.
• Object (O) – The direct object is the person or thing being acted upon.

The minimum required for a grammatical sentence is a subject (i.e., the person or thing doing or being something) followed by a verb (i.e., the action or state of being):

The sentence above has only two words: The proper noun “Steve” and the verb “dances.” This is a grammatical sentence, but only if we use those words in the order shown. If we were to reverse the word order here (i.e., “Dances Steve”), it would not make sense.

Any sentence with a transitive verb will also require a direct object after the verb. This “object” is the thing being acted upon in the sentence. For example:

In the sentence above, the subject (“Sally”) acts upon (“kicks”) the object (“the ball”). Any order other than SVO here would be ungrammatical without adding extra words. As such, this basic word order is often the clearest, most concise option available.

An indirect object receives the direct object in a sentence, such as in the following:

To break this down a bit, in this case:

• “Jimmy” is the subject.
• The verb is “gave.”
• The direct object is “the present.”
• And “his grandad” is the indirect object.

As you can see, then, following a preposition like “to” or “for,” we place the indirect object after the object. However, if we omit the preposition from the sentence, the indirect object would go before the object (making the correct order subject + verb + indirect object + object):

This distinction is key, so it’s always worth checking whether your sentence contains a preposition if you’re unsure about the correct word order.

Letter omission and letter addition are common causes of spelling errors:

• Omitting a letter means missing it from a word.
• Letter addition means adding an unnecessary letter to a word.

There is no simple rule for spotting these errors, but they are especially common in words that contain double letters. In some cases, people miss a double letter from a word:

In other cases, people may add a second double letter to a word that only needs one:

As such, make sure to double check any word with a double letter that you’re unsure about.

Silent letters are just what they sound like: letters or letter combinations that are part of how a word is spelled, but which aren’t pronounced when a word is spoken.

Take the word “gnome,” for example. The “g” at the start of this word is silent, so it’s pronounced as if it were spelled “nome.” We see the same in words like “gnaw” and “sign.”

There are no strict rules in English about when a letter is silent. You can, however, learn some common silent letter combinations so that you know what to look for:

• B after M or before T (e.g., doubt or crumb)
• C after S in some words (e.g., scissors or ascent)
• G before N (e.g., gnat or foreign)
• K before N (e.g., knee or knowledge)
• N after M (e.g., hymn or column)
• P before S, T, or N (e.g., psychic, receipt, or pneumonia)
• T before S in the middle of a word (e.g., castle or listen)
• W before R or sometimes after S (e.g., write or sword)

Keep in mind that these letter combinations aren’t always silent. This is particularly true when the two letters are part of different syllables, such as in the word “magnet.”

There are also cases that don’t follow any obvious pattern. For example, while the “c” after the “s” is silent in a word like “muscle,” it is pronounced in words like “score” and “disc.” This makes silent letters tricky to master, but practicing difficult words will definitely help!

The phrase “i before e except after c” reminds us that “i” comes before “e” in many words, except when it is preceded by a “c.” This typically applies when the “ei/ie” letter combination is pronounced as an “ee” sound, such as in the following terms:

“I before e except after c” can therefore be a helpful rule if you’re not sure how to spell a word. However, there are several exceptions to this rule, including:

• Words that end “cy” when adding a suffix (e.g., “bouncy” to “bounciest”)
• Words that don’t contain an “ee” sound (e.g., “beige” or “foreign”)

There are also a few words that contain an “ee” sound and are spelled with an “-ei-” despite it not following a “c” (e.g., “caffeine,” “weird,” and “seize”). As such, it always helps to check a dictionary if you’re not sure whether to use “ei” or “ie” in a word.

When a verb ends in a consonant followed by “-y,” we usually change the “y” to “i” or “ie” when adding a suffix or forming a plural. For example:

The example above shows a singular term and its plural. Other examples include:

• Past tense verbs (hurry → hurried)
• Singular present tense verbs (try → tries)
• Comparatives (happy → happier)
• Superlatives (happy → happiest)
• Adverbs formed from adjectives (happy → happily)

There are exceptions here, too, though (e.g., the comparative and superlative forms of “sly” can be spelled “slyest/sliest” and “slyer/slier”), so keep your dictionary handy!

The “doubling up” rule (also known as the 1:1:1 rule) states that, when adding a vowel suffix (e.g., “-ing” or “-ed”) to a single-syllable word that ends with one vowel followed by one consonant, we should double the final consonant. For example:

With longer words, we usually do the same when the final syllable is stressed. However, we don’t do it when the final syllable in a word before a suffix is unstressed:

However, we do not usually double the letters “w,” “x,” or “y” in English, so single syllable words that end in a vowel plus “w,” “x” or “y” don’t require doubling the final letter when adding a vowel suffix (e.g., play → player, snow → snowing, box → boxed).

Most of the time, if a word ends in “e,” you will need to drop it when adding a suffix that ends in a vowel. For instance, “dance” becomes “dancing” (not “danceing”).

Common suffixes that require dropping an “e” include:

However, there are some exceptions to this rule:

• Words that end in double vowels (e.g., “-ee” or “-oe”) don’t always require the final “e” to be dropped when adding a vowel suffix (e.g., shoe → shoeing).
• Do not drop the final “e” from words that end with either “-ce” or “-ge” when adding a suffix that starts with an “a” or an “o” (e.g., advantage → advantageous).

As elsewhere, then, you may want to keep a dictionary on hand in case you’re not sure whether to drop the final “e” in a word when adding a vowel suffix.

When a word ends in an “-f” or “-fe,” the general rule is to replace the “-f” or “-fe” with “-ves” when forming a plural (like how “calf” becomes “calves”). Examples include:

This does not apply when a word ends in a “-ff,” so “sheriff” becomes “sheriffs” (not “sherives”). Other exceptions include “chiefs” and “beliefs.”

Often originating in Latin, words that end in “-us” typically take an “-i” in plural form:

Again, there are exceptions to this rule, notably “virus” (which always becomes “viruses” in modern English). In other cases, you can use either the Latin ending or a regular plural version (e.g., “hippopotamuses” and “abacuses”). Generally, we’d recommend sticking to regular plural endings where possible, as these are usually clearer.

Other Latin-derived word endings include “-on” and “-um,” which take an “-a” when forming a traditional plural (so “criterion” becomes “criteria”). Additional examples include:

As with “-us” word endings, though, you may be able to use a regular plural ending for some words. “Stadiums,” for instance, is now much more common than “stadia.”

Words with “-is,” “-ex,” or “-ix” endings tend to change to “-es” or “-ices” in their plural forms. For instance, “analysis” becomes “analyses” and “appendix” becomes “appendices”:

Some words change their vowel sound as a plural, like how “foot” becomes “feet”. See also:

Some irregular plurals actually stay the same as the singular form of the word. Examples include “squid,” “sheep,” “fish,” and “species.” For instance, both “a fish” (singular) and “a shoal of fish” (plural) are correct. It’s also worth noting that uncountable nouns, like “water” or “sand,” stay the same regardless of the amount being described.

If you are unsure about the correct plural form for a word, check a dictionary.

“Affect” and “effect” are related terms, but there is a key difference:

• Affect is typically a verb meaning “change or influence.”
• Effect is primarily a noun meaning “consequence or result.”

For instance, we could use “affect” in a sentence as follows:

Here, “affect” refers to the act of changing something. But if we wanted to discuss the result of such an action, we would need the noun “effect” instead:

“Accept” and “except” are both common words, but they differ in meaning:

• Accept is a verb that usually means “receive willingly or admit.”
• Except is usually a preposition or conjunction meaning “apart from or excluding.”

For instance, we could use each term as follows:

“To” and “too” sound identical and look similar written down. They’re also very common terms in English writing. However, they play very different roles in a sentence.

To is usually a preposition. It has several meanings, including (among others) indicating direction or duration, identifying a recipient, or making comparisons.

It can also be used before an infinitive verb to express a purpose or give an opinion:

Too, meanwhile, is an adverb that can mean either “as well” or “excessively”:

Another word that sounds similar to the above is “two” (i.e., the number “2”). But this term is clearly distinct in spelling, so it is easy to tell it apart from “to” and “too.”

While these terms are easy to mix up, they have very different meanings:

• Its is a possessive pronoun (i.e., it shows that something belongs to an “it”).
• It’s is a contraction of “it is” or “it has.”

This may seem confusing, as we often associate an apostrophe with possession. For instance, to show ownership with a regular noun, we add an apostrophe plus “s.” However, this is not the case with possessive pronouns like “its,” “his,” or “her.”

A contraction, meanwhile, will always need an apostrophe. As such, if you’re going to use “it’s” in a sentence, try writing it as “it is” or “it has” and see if it makes sense. If not, you probably need “its” instead. And remember not to use contractions in formal writing!

As above, here we have a possessive pronoun and a contraction:

• Your is a possessive pronoun (i.e., it shows that something belongs to a “you”).
• You’re is a contraction of “you are.”

The same rules as above apply here, too. As such, if you’re going to use “you’re” in a sentence, try writing it as “you are” to see if it makes sense. If not, it may be that you need the possessive pronoun “your” instead. And, again, make sure not to use contractions in formal writing! You will always be better off writing out “you are” in full if you need to be formal.

In this case, we have three words that sound similar but differ in meaning:

• Their is a possessive pronoun (i.e., it shows that something belongs to a “they”).
• They’re is a contraction of “they are.”
• There can be an adverb or pronoun and indicates a location or position.

We would use each term in a sentence as follows:

As with “it’s” and “you’re,” remember to avoid contractions in formal writing. In an essay, for example, you will always be better off writing “they are” than “they’re.”

This time, we have a verb, an adverb, and another contraction:

• Were is a past tense form of the verb “be.”
• Where is usually an adverb that indicates a location or position.
• We’re is a contraction of “we are.”

The trickiest terms here are “were” and “we’re,” as both include forms of the verb “be.” However, as with the other contractions above, the apostrophe is a giveaway here! So if you’re not sure whether to use “we’re” in a sentence, try writing it as “we are” instead and see if it fits. If not, you probably need “were” or “where” instead.

As for when to use “were” or “was” (another past tense form of “be”), see the table below:

“Lay” and “lie” sound different, so it is easy to tell them apart as present tense verbs:

• Lay means “put something down or place it horizontally.”
• Lie can mean either “recline” or “tell an untruth.”

The tricky part of these words is that “lay” is also the simple past tense of “lie” when used to mean “recline” (but not for “tell an untruth”). Try to remember the following:

Although these words sound similar, they play very different roles in a sentence:

• Are is the second-person singular present tense (i.e., “You are”) and plural present tense (i.e., “We are,” “You are,” “They are,” etc.) form of the verb “be.”
• Our is a first-person plural possessive pronoun, meaning “belonging to us.”

As long as you remember that “are” is a verb and “our” is a pronoun, though, it should be easy to avoid mixing up these terms in your writing.

As well as words that sound similar, English has plenty of synonyms (i.e., words with the same meaning as one another). Sometimes, this means you can use words interchangeably. For instance, “begin” and “start” can both be used as follows:

Unfortunately, some words with similar meanings differ in how they are used. For example, the words “quick” and “fast” are both adjectives that mean “speedy.” But “quick” also implies brevity, which is not the case with “fast.” As such, a short conversation could be described as a “quick chat,” but a “fast chat” would imply talking at high speed!

This is why it’s important to check a dictionary when using synonyms, especially if it is an unfamiliar word from a thesaurus. Asking a native speaker can also help!

The term “that” is used when introducing a restrictive relative clause. This is a clause that restricts the meaning of the sentence, such as the following:

In the above, the phrase “that we rented” identifies the specific houses being described (i.e., the houses that were rented, not those we didn’t rent). It is thus a “restrictive” clause and cannot be removed without changing the meaning of the sentence.

By contrast, “which” is used when introducing a non-restrictive relative clause. This is a clause that doesn’t restrict the meaning of the sentence:

The “which” clause here introduces new information, but isn’t needed for the main point of the sentence (i.e., that all the houses were infested). The extra clause simply tells us that we rented “all the houses” but not which houses we’re referring to. As such, we could remove “which we rented” without changing the overall meaning of the sentence.

You’ll notice that the “which” clause is also set apart with commas. This is to show that it is bonus information, not essential to the main clause. We do the same thing when a non-restrictive relative clause appears at the end of the sentence:

Keeping in mind the differences above, knowing whether to use “that” or “which” at any given point requires asking, “Does this clause change the meaning of my sentence?”

• If removing it would change the meaning of the sentence, you need to use “that.” This is known as a restrictive relative clause.
• If removing the detail doesn’t change the overall meaning of the sentence, you should use “which” and set the clause apart with commas. This is known as a non-restrictive relative clause.

The rules above are correct for American English. And you’ll be fine if you use the terms “that” and “which” like this in any English dialect. However, in British English and other similar English dialects, you can also use “which” for restrictive relative clauses.

The subject and verb in a sentence need to “agree.” This basically means “match in number,” so we use singular subjects with singular verbs and plural subjects with plural verbs.

For example, in the present tense singular, we usually add an “s” after the base verb form (e.g., sing becomes sings). If we have a plural subject, though, we use the base verb form:

And in the simple past tense, there’s usually no difference between singular and plural verbs:

This should be fairly simple to remember. But there are some cases where it is less clear whether to use a singular or plural verb. We’ll look at these below.

A “compound subject” is a subject made up of two nouns joined by a conjunction. When two subjects are joined with the coordinating conjunction “and,” we always use a plural verb:

However, when using “either/or” or “neither/nor” in a compound subject, whether to use a singular or plural verb depends on the noun nearest to the verb:

In the above, we use the singular “is” when the singular noun “boy” comes after “or,” but we use the plural verb “are” when the plural noun “girls” comes after the conjunction.

You can use a parenthetical statement – extra information set apart from the main part of a sentence with brackets, dashes, or commas – between a subject and a verb. However, the verb should agree with the main subject sentence regardless.

In the following, for example, we use the singular verb “goes” because the dog is only mentioned within commas, not as part of the subject of the sentence:

If you’re not sure whether to use a singular or plural verb in a sentence with parenthetical information, then, try cutting it down to the main clause and see what fits best:

In American English, collective nouns (i.e., nouns that refer to a group of things) typically require a singular verb. However, you can use a plural verb with a collective noun if the members of the group are acting as separate individuals:

Here, we use the singular verb “is” to describe a team that is working together to win. But we use the plural verb “are” when the players are acting as individuals.

Mass (or “non-count”) nouns are similar, since they take singular verbs despite referring to a mass substance (e.g., “milk,” “water,” or “sand”):

Here, it doesn’t matter how much we’re discussing, we always use the singular form.

As usual in English, there are exceptions to the rules above. The main two are:

• The first-person “I” and the singular second-person “you” reverse the usual rules in the present tense (e.g., we say “I sing” not “I sings,” even though “I” is singular).
• When using a past participle, the auxiliary verb (e.g., “is”/“are” or “has”/“have”) may change depending on whether the subject is singular or plural (e.g., “The boy has finished his homework” vs. “The boys have finished their homework”).

As long as you can remember these, you should be able to avoid most subject–verb agreement errors in your writing. But since sentence structure can affect the correct verb form, it also helps to ask a friend or proofreader if you’re unsure about anything.

Most verbs are easy to understand because their simple past tense and past participle forms all end with the letters “-ed.” For instance, the verb “sail” becomes “sailed,” “bake” becomes “baked,” and “kick” becomes “kicked.” These are known as regular verbs.

As above, the “y-to-i” rule applies here, so we usually add “-ied” instead when a verb ends in “y” (e.g., “hurry” becomes “hurried”). But these are still “regular” verbs because their past tense and past participle forms follow a regular pattern

However, some verbs do not follow a pattern. These are known as “irregular verbs.” For example, the simple present tense verb “break” does not become “breaked,” but changes into “broke” (simple past tense) and “broken” (past participle). Other examples include:

As you can see, there is no real pattern to how irregular verbs behave:

• Some change just one letter in different forms (e.g., drink > drank > drunk).
• Others change more significantly (e.g., think > thought).
• In some cases, the simple past tense and past participle forms are the same.
• Some words use a different term for past tense and past participle forms.
• Others don’t change from the base form in either case (e.g., cut).

The common term “be” is a standout irregular verb. “Be” is the infinitive form (i.e., “to be”), but usually you will need one of its many variations:

Irregular verbs can, therefore, be a bit confusing! Our advice is to watch out for these terms when reading to learn how they’re used. Checking unusual terms in a dictionary and having your work proofread to correct any verb-based errors is also a good idea.

Verb “tense” gives us a time reference for an action. At its most basic, for instance, we distinguish between something that is currently happening with something that happened in the past by changing the form of the verb (e.g., I walk → I walked).

The correct tense to use will depend on what you are trying to express. However, we can summarize the tenses in English and their uses as follows:

If you are unsure about the verb tense in your writing:

1. Think about when the action you’re describing happens or happened. You can use the table above to quickly see what each tense is typically used for.
2. Make sure you use tenses consistently.
3. Don’t be afraid to ask a native English speaking friend or proofreader to check that the verb tenses are clear throughout your writing.

This should help you avoid errors related to verb form in your work.

Apostrophes are how we show that something belongs to someone or something else. Typically, we do this by adding an apostrophe and an “s” like this:

The main exception to this rule is possessive pronouns (e.g., “its,” “his,” “her”), which do not require an apostrophe. So, for example, the pronoun “it” becomes “its” to show possession:

See the section on “its” and “it is” for more on this distinction. However, we can also look at some more cases where possessive apostrophes can be confusing.

When a word already ends in the letter “s,” you can either:

1. Add an apostrophe plus another “s” (e.g., Alanis’s grasp of irony…)
2. Or just use the apostrophe by itself (e.g., Alanis’ grasp of irony…)

Both are acceptable in modern English as long as you’re consistent. However, if you have a style guide, you may want to check it for advice on which approach to use.

Possessive apostrophes always go after the final “s” in a plural. If we wanted to talk about two dogs with empty food bowls, for example, the apostrophe placement would be crucial:

The first sentence above suggests multiple dogs and multiple bowls. But the second implies one dog with more than one bowl. And while this second sentence is not ungrammatical, it would still be an error if we were trying to discuss the bowls of more than one dog.

When two or more people own one thing, the correct place to use an apostrophe comes down to whether you’re talking about separate or joint ownership:

1. 1. When two or more people separately own the same type of thing, you should add an apostrophe after each person’s name.
   2. If two or more people jointly own something, you should treat them as a single “subject” and you only need one apostrophe.

For example, if two people both had a stamp collection, we might say:

Here, we use an apostrophe for both Tim and Rachel because we’re talking about two people with two separate stamp collections. This is also why we use the plural noun “collections” and plural verb “are.” But let’s imagine that Tim and Rachel share a stamp collection instead:

In this case, we only use one apostrophe because “Tim and Rachel” are a single unit known as a compound subject. This is also reflected in the singular noun “collection” and the singular verb “is,” so we can see the sentence is about a jointly owned collection.

This distinction can be harder to spot when dealing with a mass noun:

In the first sentence, Bob and Beryl have each lost their own luggage. In the second, Bob and Beryl have lost their shared luggage. And since “luggage” is always singular, we need the apostrophes to tell us who owns what. In cases like this, apostrophe use is crucial!

We use an apostrophe in contractions to indicate missing letters:

Another common contraction is to add an “-’s” to a word when it’s followed by “is” or “has”:

The main thing to note here is that you should not typically use contractions in formal writing (e.g., an essay). In such cases, it is much better to write out the full terms.

One common error is to put an apostrophe before an “s” when forming a plural. But this is NEVER CORRECT! The plural of “dinosaur,” for example, is “dinosaurs,” not “dinosaur’s.”

So apostrophes can be used to show:

• Who owns something (i.e., possession)
• Missing letters in a contraction

But they are not needed and should not be used if you’re simply forming a plural.

Or it can occur when someone uses a comma in place of a period (i.e., a “comma splice”):

If you see a run-on sentence in your writing, you can fix it in various ways:

1. Placing a period between each clause.
2. Adding a coordinating conjunction after the comma.
3. Replacing the comma with a semicolon.
4. Changing the first clause into a subordinate clause.

We will look at each of these in a little more detail below.

We can fix run-on sentences by using a period to separate the clauses:

This is often the simplest way to fix comma splices. However, if you want to emphasize or clarify the connection between two sentences, you have some alternatives available.

Conjunctions are connecting words, so we can add one to fix a run-on sentence:

Note that we still have a comma here between the clauses before the conjunction. This isn’t strictly necessary if connecting short sentences, but it is good practice for clear writing.

We can use a semicolon between two clauses to show they are related:

Remember, though, that semicolons can only be used to connect full sentences.

While commas can’t be used to connect two main clauses, they can be used when a subordinate clause comes before the main clause in a sentence. Thus, if we change the first clause in a run-on sentence to a subordinate clause, we can fix the error:

As shown above, a subordinate clause includes a subordinating conjunction – in this case, “because” – and does not form a full sentence by itself. But by changing the first clause into a subordinate clause, we now have a grammatical sentence.

We could also rearrange the sentence so the main clause comes first:

In this case, we do not need a comma to separate the two clauses.

The comparative “bigger” here shows that we’re comparing the size of two houses.

We use superlatives, meanwhile, to show that something has the most or highest degree of some quality. However, this only applies when discussing a group of at least three things:

Here, for instance, we’re discussing the entire neighborhood, and we use the superlative “biggest” because there may be many houses in a neighborhood.

However, it isn’t always obvious how to form the comparative or superlative form of a word. As such, we’ll look at some helpful guidelines for using these terms below.

Many comparatives end with “-er” and many superlatives end with “-est.” These spellings are used when forming a comparative or superlative from either of the following:

1. All single-syllable words (e.g., small → smaller → smallest)
2. Most two-syllable terms (e.g., happy → happier → happiest)

In other cases, we form comparatives and superlatives by adding the words “more” or “most” before an adjective or adverb. This is applies when the base term is:

1. Two syllables and ends “-ful,” “-ous,” or “-less” (e.g., famous → more famous → most famous)
2. An adverb ending in “-ly” (e.g., slowly → more slowly → most slowly)
3. Three syllables or more (e.g., interesting → more interesting → most interesting)

Some two-syllable words can use either approach (e.g., you can say either “more narrow” or “narrower”). However, “-er” and “-est” endings are more concise and often preferable.

We also have some irregular comparative and superlative terms, including common words such as “better” and “best.” These particular terms are the comparative and superlative forms of “good” and “well” (hence we don’t say “gooder” or “goodest”).

Key irregular comparatives and superlatives to remember include:

As you can see, these terms don’t follow a specific pattern. The best way to avoid errors is thus to memorize the comparative and superlative forms of irregular adjectives and adverbs.