The large majority of -ize/-ise verbs come from Greek words ending in -ιζειν [-izein] (sometimes via Latin, in which they end in -izare). English adopted many o

The large majority of -ize/-ise verbs come from Greek words ending in -ιζειν [-izein] (sometimes via Latin, in which they end in -izare). English adopted many of these words via the French, which lacks "Z" as a native letter, and so the -ise spelling. Americans reverted to the -ize spelling on the principle of spelling words as they sound (a foreign concept to the language, we must all agree), and much of educated Britain likewise used the -ize spelling on etymological grounds. (Thus Oxford spelling [en-GB-oed].) Esteemed English institutions such as the Oxford University Press and Cambridge University Press still use the -ize spelling, as did The Times, until it came to be perceived as an Americanism in the 1980s. International English, such as that used by the United Nations, follows Oxford spelling and so uses -ize.