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Is it “Behaviour” or “Behavior”?

"Behaviour" or "Behavior"

Between behaviour 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 can influence the behaviour/behavior of their children.

  • UK English spells “behaviour” with the vowel “u”.

  • US English spells “behavior” without “u”.

UK EnglishUS English
We were grateful for the gracious behaviour of our hostess.The children were rewarded for good behavior.

Other “-our”/”-or” words

Other words that use “-our” / “-or” follow the same spelling pattern across British and American English preferences. As you’ll see below, it includes a fair number of words which are regularly used.

UK EnglishUS English

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 Englishbehaviourally, 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.

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 wordsUK English vs. US English
former vs. latterburned or burnt?
bear with vs. bare withcolor or colour?
breathe or breathfavorite vs. favourite
compliment vs. complementsmelled or smelt?
effect vs. affectgray or grey?
elude or alludefavor vs. favour
it’s or itsanalyze or analyse?


  1. Harper, Douglas. “Etymology of behaviour.” Online Etymology Dictionary, Accessed 16 January, 2024.

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