Might I be allowed to offer my observation on the old chestnut that is the position of the apostrophe?
It seems to me that many of the errors arise from schoolchildren being told that there are 2 options: apostrophe S, and S apostrophe.
Surely there is only the former - ‘S to denote ownership. However, if the word (to which ownership is to be ascribed) already ends in an S, (as happens with feminine forms, most plurals, a few proper names etc) it looks odd with S’S, and is harder to pronounce, so the S (of ‘S) is dispensed with.
It really doesn’t make the notation S’. Eg the ladies’ bags was never “ ladie” with S’, but ladies with ‘s, and then with the second S removed to avoid S’S.