Between behavior or behaviour, which is the correct spelling?
It’s a bit of a trick question, because the answer depends on geography (as you may have guessed … if you’ve been keeping up with your regularly scheduled grammar-flexing!)
Behaviour or behavior?
Behaviour and behavior are two spellings of the same word that describes the way someone acts or the things they do; e.g., parents influence the behaviour/behavior of their children.
The dog’s behavior during the thunderstorm was quite erratic. .
Her impeccable behaviour at the formal dinner impressed everyone. .
The childs behaveour was unacceptable. .
The cat’s behavoir was unsettling. .
- UK English spells “behaviour” with the vowel “u”.
- US English spells “behavior” without the “u”.
| UK English/British English | US English/American English |
| We were grateful for the gracious behaviour of our hostess. | The children were rewarded for good behavior. |
Other “-our”/”-or” words
This chart shows other words that use “-our” / “-or”, depending on British and American English preferences. As you’ll see below, lots of words follow this spelling pattern, so it’s beneficial to learn their correct spelling!
| UK English | US English |
| favour | favor |
| labour | labor |
| behaviour | behavior |
| colour | color |
| humour | neighbor |
| endeavour | endeavor |
Other forms of the word behaviour
Other forms of the word also follow the same spelling conventions based on US/UK English:
| US English | [adverb] behaviorally, [adjective] behavioral.[verb] behave |
|---|---|
| UK English | behaviourally, behavioural. |
“Behaviour” / “behavior”, used in sentences
His behaviour/behavior towards her was becoming more and more aggressive.
I noticed a change in his behaviour/behavior.
I know you were upset, but that doesn’t excuse your behaviour/behavior.
He had his jail term cut for good behaviour/behavior.
“behavior” (US) and “behaviour” (UK), associate the “u” in “behaviour” with “UK.”.
Behaviour, synonyms
- conduct
- etiquette
- action
- bearing
- manners
- habits
- deportment
- way of doing things
- way of carrying oneself
Origin of the word
From Etymonline on behaviour:
“manner of behaving (whether good or bad), conduct, manners,” late 15c., essentially from behave, but with ending from Middle English havour “possession,” a word altered (by influence of have) from aver, noun use of Old French verb aveir “to have.”
Learn more about US English vs. UK English
| Commonly misused words | UK English vs. US English |
|---|---|
| former vs. latter | burned or burnt? |
| bear with vs. bare with | color or colour? |
| breathe or breath | favorite vs. favourite |
| compliment vs. complement | smelled or smelt? |
| effect vs. affect | gray or grey? |
| elude or allude | favor vs. favour |
| it’s or its | analyze or analyse? |
Sources
- Harper, Douglas. “Etymology of behaviour.” Online Etymology Dictionary, Accessed 16 January, 2024.
Work Sheet
Which spelling of the word describing how someone acts is typically preferred in British English?
According to the post, the main factor determining whether to use “behaviour” or “behavior” is:
If you are writing for an audience in the United States, which spelling should you generally use?
Which of the following words, mentioned in the post, also follows the ‘-our’ (UK) / ‘-or’ (US) spelling pattern?
The study tip in the post suggests associating the ‘u’ in ‘behaviour’ with which country?
The dog’s during the thunderstorm was quite erratic. (US spelling preferred)
Her impeccable at the formal dinner impressed everyone. (UK spelling preferred)
We were grateful for the gracious of our hostess. (UK spelling from post example)
The children were rewarded for good . (US spelling from post example)
The company implemented new guidelines for its employees. (Both forms could fit, but check options – testing the -al form differentiation based on common usage or the pattern itself)
Frequently Asked Questions
Is “behavior” or “behaviour” correct?
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When do I use “behavior” spelling?
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When do I use “behaviour” spelling?
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Do related forms follow this rule?
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Do other words follow this spelling?
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Yash, D. "Is it “Behaviour” or “Behavior”?." Grammarflex, Jun 21, 2025, https://www.grammarflex.com/is-it-behaviour-or-behavior/.
