An English question about s/z Some verbs end with -ise, some with -ize. I checked the dictionary, and here are some proper writings: Z: conceptualiZe immortaliZe hypnotiZe generaliZe organiZe idoliZe apologiZe realiZe criticiZe (some also have a version with a s) ... S: surpriSe surmiSe despiSe riSe wiSe ... What is the rule? Also, what about the -iZation/-iSation words? It is generaliZation, organiZation, realiZation ... Are s and z sometimes interchangeable? Is this an American English vs. British English issue?