Apostrophes
Apostrophe to show plurals
This is an area that sparks some debate, as rules are changing over time. It is, however, accepted, that an apostrophe is used to show:
- the plurals of single letters: You must mind your p’s and q’s.
- abbreviations that have letters divided by full stops: three Ph.D.’s, two B.A.’s
More info
- When to form a plural with an apostrophe (Daily Writing Tips)