Word Choice: Extent vs. Extend

Usually, our ‘Word Choice’ posts cover homophones (i.e. words that sound alike despite being spelled differently and having different uses). On this occasion, however, we’re essentially looking at two variations of the same word: ‘extent’ and ‘extend’.

Both of these terms relate to the scope, length or degree of something, but one is a noun and the other is a verb. Confusing them in your written work can, therefore, affect its clarity.

Yet their similarity in spelling means it’s easy to get them mixed up if you’re not sure what each means.

Extent (The Length or Degree of Something)

‘Extent’ is a noun, broadly meaning ‘the length or degree of something’. In a physical sense, this refers to the size or spatial dimensions of something:

The extent of the reserve is clearly shown on the map.

In a non-physical sense, it refers to the significance or scope of something:

We weren’t prepared for the extent of the damage caused.

In both cases, however, ‘extent’ is always thing, rather than an action.

Extend (To Stretch Out or Enlarge)

The verb ‘extend’ also has physical and non-physical senses, but in this case both are actions. In a physical sense, ‘extend’ means to stretch out or place something at full length:

Extending her arm, Sarah reached out and plucked an apple from the tree.

In a non-physical sense, ‘extend’ can refer to enlarging the scope of something:

These results justify extending the project to new populations.

Or increasing the length of time over which something occurs:

To ensure safety, we will extend the testing period for three months.

It can also be used when offering something formally:

In thanks for your valuable assistance, I’d like to extend an invitation to the book launch.

In all cases, though, ‘extend’ is always an action.

‘The Extent/Extend to Which…’

The most common place that these terms get confused is when describing, or asking about, the degree to which something applies.

For instance, people sometimes write that something is true to a greater or lesser ‘extend’, or say they’re investigating ‘the extend to which’ something is true.

However, as the definitions above should tell you, this use of ‘extend’ is incorrect. Since these cases refer to a thing, not an action, the correct term would always be ‘extent’:

To a great extent, psychological explanations prove satisfactory.

This essay explores the extent to which consumers value designer labels.

Extent or Extend?

These words look similar on paper, but it’s easy to know which one to use as long as you keep in mind that one is a noun and the other a verb. Remember:

Extent (noun) = The length or degree of something

Extend (verb) = To stretch out, enlarge, increase or offer something