IANALinguist, but like a lot of 'fun facts', I think that's only half true. Saying the 'z' spellings are invariably the originals is as wrong as saying that for

IANALinguist, but like a lot of 'fun facts', I think that's only half true. Saying the 'z' spellings are invariably the originals is as wrong as saying that for 's' endings. The idea is that the words originally came from ancient Greek, where they had the ending -ιζειν, pronounced with a z. The trouble with that is that not all these words did come from the Greek. E.g. realize/realise was (IIRC) a French invention, and they spelled it réaliser. And even in the ones that did come from the Greek, not all of them had the -ιζειν ending - e.g. analyse/analyze was ἀνα·λύω (pronounced analuo); I guess the French gave it the -yser ending. (The real solution, IMO, is to reject the idea that the 'correct' spelling of a word is the one closer to how it was spelled in the language it was invented in).