I've been brought up believing that most of the words that have suffix with '-ize' or '-ized' is the American English form and the British English forms use (most of the time) '-ise' or '-ised' as the equivalent.

Two questions:

1) What is the rule, if any, around exception cases, i.e. choice of one or the other in a single form (dialect?) of English?

2) I have read recently, on Wikipedia admittedly, that the etymology of these terms is such that the correct form anyway, for all English from Greek roots, is '-ized' using the 'z'. This contradicts what I see, and what I've been brought up to know. But is that correct - it was from this site:


and the Wikipedia page.

I am not saying it is wrong, but I wanted to verify if this is the case...as I say, it runs contrary to what I know, but came across it by chance and it is a very difficult habit to get out of. I don't want to do it (as a British person, using '-ise' all the time) to the American English version, when actually it would be wrong.

On a more pragmatic matter, I wonder if doing this is a bad idea anyway in the UK, since most people are told the 's' version is correct.

Finally, etymologically, what is the reason for this shift across, whatever the reason is? And is it something that is 'wrong' or more 'the development of language over time'.

I don't understand why America would revert to 'z' after the development of English in Britain towards 's', given that Greek is the origin. I understood British people discovered America and brought British English over there. Unless, and probably quite likely, I haven't got a clue re the history between the two nations (and this is not meant to offend, I just have a confused understanding - sorry if it does).

  • Wait, what? British people didn't discover America, they just started moving there once it had already been (re)discovered. Sep 3, 2015 at 8:14
  • Fourteen years after the British set fire to the White House in 1814, Noah Webster, apparently still pissed off, published his famous dictionary that revised many British spellings. Which showed the British even better than the Battle of New Orleans.
    – deadrat
    Sep 3, 2015 at 8:32
  • Etymology doesn't determine correct spelling. Also, you can't tell what the correct etymology is just from "what [you] see and what [you]'ve been brought up to know." A good dictionary should have notes on both the etymology and the standard spelling(s) of words.
    – herisson
    Sep 3, 2015 at 8:40
  • @sumelic I'd say 'Etymology doesn't determine correct spelling' isn't quite right. From AHDEL: << etymology The origin and historical development of a linguistic form as shown by determining its basic elements, earliest known use, and changes in form and meaning ...' >> It's just that many people don't consider that yesterday (09/03/2015 amstc) is still history, and development is continuous. Sep 3, 2015 at 9:57
  • For further research, you may be interested in this ngram that shows results from published works for 'realise/realize' books.google.com/ngrams/… --- Note that, since about 1930, British usage of -ize appears to have overtaken -ise. I didn't analyse why Sep 3, 2015 at 10:43

1 Answer 1


Indeed, Greek is one linguistic source in questions of "-ize" vs. "-ise", with the latter looking to the added lens of French. Greek's "zeta" / "-ize" is preferred (but not exclusively so) in the U.S. while French intervocalic "s" / "-ise" is preferred in Britain. There are exceptions: the French "s" prevails in both countries in words such as "surprise" (from the past participle of French "surprendre") where there is no equivalent cognate from Greek. 19th century American prescriptions for spelling favored classical languages (Latin as well as Greek) as sources, while British English never "forgot" (linguistically) the influence of the Norman Conquest, which brought French to Anglo-Saxon shores - hence the continued preference in Britain for the presence of "u" where it occurs in French, e.g. UK: vapour (Fr. vapeur) as opposed to US: vapor (Latin vapor).

  • Thanks for this too, @Odo edBayeux...maybe I'm not thinking clearly at this time of morning, but I was wondering then, is it correct that French is predominantly a Latin inspired language (was I supposed to put a hyphen between Latin and inspired, btw?), and that's why it has the 's' (on (by?) that logic) or is there some other reason why they might have moved away from the 'z'? Sorry for my compound questions, I've become paranoid since I started using these forums! Sep 4, 2015 at 4:59

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