A long time ago

I have a strong memory of being taught about apostrophes in our grammar lessons at school in the 1950s. We were definitely taught to put an apostrophe in that decade and to write the 1950’s. I’m not quite sure what the reasoning was for putting the apostrophe in, but I’m glad that modern usage has decided that we’re dealing with a plural noun and that no apostrophe is required.

Mrs Walsh, our English teacher, is probably turning in her grave to see that we now refer to MPs and BMWs and CDs and FAQs, no longer using an apostrophe in these acronyms. There is no need for an apostrophe in CDs or MPs unless you want to show possession e.g. the CD’s cover or the MP’s office. You don’t even need an apostrophe for one letter plurals as in ‘I got two Bs and four Cs in my exams.’  But if there might be confusion, you would be justified in popping one in e.g. ‘This sentence has too many I’s’ benefits from an apostrophe to keep ‘I’s’ from looking like ‘is’.

Room for manoeuvre

The apostrophe still gives rise to dispute and even grammar authorities differ over its correct use. In the familiar phrase ‘do’s and don’ts’, Macmillan Dictionary includes an apostrophe in do’s, while other authorities, such as the Oxford Manual of Style, prescribe the more consistent but definitely odd looking dos and don’ts. There are reasonable arguments for and against both styles.

Sometimes it can be a good idea to avoid the problem by rearranging the sentence so that ‘I’ve got a long list of to-dos,’ becomes ‘I’ve got a long list of things to do.’