american english - How to know when the z can't be used instead of s in an ending?



I'm familiar with -se -ses -sation etc endings being British and the American equivalent being with z rather than s. However, I stumbled on the word "improvisation", which apparently can't be spelled with a z.


How can you know which words are spelled using 's' in American English?




Comments

Popular posts from this blog

commas - Does this sentence have too many subjunctives?

verbs - "Baby is creeping" vs. "baby is crawling" in AmE

time - English notation for hour, minutes and seconds

etymology - Origin of "s--t eating grin"

grammatical number - Use of lone apostrophe for plural?

etymology - Where does the phrase "doctored" originate?

single word requests - What do you call hypothetical inhabitants living on the Moon?