The other day at work I had a conversation with someone about whether they use -ize or -ise at the end of certain words. I said when the option arises I tend towards -ize.
“But that’s an Americanism!”, my colleague objected.
“No it’s not!” said I.
Anyway, here is what Henry W. Fowler has to say about the matter in his excellent volume A Dictionary of Modern English Usage:
-IZE, -ISE, IN VERBS. In the vast majority of the verbs that end in -ize or -ise and are pronounced -Ä«z, the ultimate source of the ending is the Greek -izo, whether the particular verb was an actual Greek one or was a Latin or French or English imitation, and whether such imitation was made by adding the termination to a Greek or another stem.
Most English printers follow the French practice of changing -ize to -ise; but the OED of the Oxford University Press, the Encyclopaedia Britannica of the Cambridge University Press, The Times, and American usage, in all of which -ize is the accepted form, carry authority enough to outweigh superior numbers.
The OED’s judgement maybe quoted: ‘In modern French the suffix has become -iser, alike in words from Greek, as baptiser, Ã©vangÃ©liser, organiser, and those formed after them from Latin, as civiliser, cicairiser, humaniser. Hence, some have used the spelling -ise in English, as in French, for all these words, and some prefer -ise in words formed in French or English from Latin elements, retaining -ize for those of Greek composition.
But the suffix itself, whatever the element to which it is added, is in its origin the Greek -izein, Latin -izare; and as the pronunciation is also with z, there is no reason why in English the special French spelling should be followed, in opposition to that which is at once etymological and phonetic’.
It must be noticed, however, that a small number of verbs, some of them in very frequent use, like advertise, devise, and surprise, do not get their -ise even remotely from the Greek -izo, and must be spelt with -s-; the more important of these are:
The difficulty of remembering which these -ise verbs are is in fact the only reason for making -ise universal, and the sacrifice of significance to case does not seem justified.
So now we know.