-ise and -ize

We follow The Economist in always using the “-ise” ending in words like “realise” and “recognise”. All these words came into English from French and Latin, which spell them with an “s”. It was only later that some of them were “corrected” to end in “z”, reflecting an earlier Greek form of the words (although most of them didn’t exist in Greek).

British English generally prefers the “-ise” ending, but accepts the “-ize” ending. Some publishers, including Penguin, prefer the “-ize” ending, which is standard for American English.

Where “-ize” is preferred, you must remember that there are some exceptions where the ending of the word does not come from the active suffix. “Excise” should always be spelt with an “s” because it comes from “excisus” the past participle of the Latin word formed from “ex-” and “caedere”, meaning “to cut out”.

Some other words that should always end in “-ise” are:

• advertise
• advise
• chastise
• comprise
• compromise
• despise
• devise
• enfranchise
• exercise
• improvise
• merchandise
• revise
• supervise
• surmise
• surprise
• televise

You should check your client’s house style and comply with it.