If you are preparing for IELTS, then you are probably aware that there is a difference between British and American English. These versions of English differ in various ways, including the following:

  • spelling
  • pronunciation
  • word choice (i.e. lorry vs truck)

Today, we are going to look at the different spellings in each form of English.

British vs American Spelling – Why does it matter?

Before we look at the different spellings that are found in British and American English, let’s ask why it really matters. After all, isn’t English just English?

It is true that some people make more of the differences between British and American English than they should. If you speak English well, it should be pretty easy to understand most British and American speakers when they talk or write because the differences are generally minor.

In IELTS, you can use either British or American English, but you should try to avoid mixing them. That doesn’t really matter in terms of pronunciation and word choice, but it does matter when it comes to spelling. If you begin your essay with British spellings and then switch to American ones, the American ones will be considered misspellings.

You can read about how these may affect your IELTS score here.

British vs American Spelling – Common Differences

Let’s now look at some differences between words in British and American spelling. I will try to group these into common rules.

1.-ise and -ize

Many verbs that end in “-ise” in British English take “-ize” in American English. For example:

  • apologise / apologize
  • organise / organize
  • specialise / specialize

You can see more examples here:

Just be aware that not all words follow this pattern. There are some verbs that end in “-ise” in both languages:

  • advise
  • comprise
  • compromise
  • despise
  • devise
  • disguise
  • exercise
  • improvise
  • revise
  • supervise
  • surprise
  • televise

Likewise, there are some verbs that always end in “-ize”:

  • capsize
  • prize

2.-our and -or

Next, we have words ending in “-our” and “-or.” Americans often joke about British people adding a superfluous “u” to your words and we British joke about Americans dropping it.

Basically, many words in English end in “-our” but in America they tend to drop the “u” and just write “-or.” For example:

  • behaviour / behavior
  • flavour / flavor
  • neighbour / neighbor

There are many more examples in this list:

Again, there are exceptions, so don’t just add or remove a “u”!

Here are words that end in “-or” in both versions of English:

  • doctor
  • donor
  • error
  • mayor
  • minor
  • motor
  • sector
  • victor

If you’re having problems with spelling, you might find this article useful.

3.-re and -er

Another common difference between British and American spelling is the inversion of “-re.” A lot of words in British English that end “-re” are inverted in American English to “-er.” For example:

  • centre / center
  • litre / liter
  • theatre / theater

Here are some more:

Again, don’t just assume that this rule applies to all words. We cannot turn “baker” into “bakre” for example!

4.l and ll with -ed and -ing endings

When a verb ends in an “l,” British will typically add another “l” before “-ed” or “-ing” endings. Americans, on the other hand, will not do this. For example:

  • travelled / traveled
  • travelling / travelling

Here are some more examples:

This also works with “-er” endings sometimes. To continue the above example, Brits would talk about a “traveller” and Americans would say “traveler.”

5.-yse and -yze

Here, we have another rule about British people using “s” and Americans choosing “z”!

In some words, British people will write “-yse” at the end and Americans will use “yze.” This is quite similar to the above rule about “-ise” and “-ize.”

A common example is “analyse” (British spelling) and “analyze” (American spelling). Here are some more:

As you can see, there aren’t many examples. This isn’t as common as the above rules.

Other Differences

Those are the most common rules, but there are other words that Brits and Americans spell differently. You can see some of them here:


Some people pretend that British and American English are totally different languages, but the differences are actually quite small. If you can remember the above rules, you should be able to read and write without worrying about regional variations. Just try to keep in mind that you should probably pick one form of English and stick to it. If you go back and forth between these two versions, you may find it lowers your IELTS writing score. (You can check your score by using my writing correction service.) You don’t need to memorise (or memorize!) thousands of words. Instead, just remember the above rules and you’ll avoid most mistakes.