The apostrophe (') has three general uses:
A) Possessive case of singular and plural nouns that don't end in s:
The boy's bike; the men's wives; the mice's ears
(note that even though men and mice are plural nouns, they do not end in s!)
B) Possessive case of singular nouns ending in s; in that case it's optional:
James's car; Charles's son; Burns' poetry
James' car; Charles' son; Burns' poetry
C) Possessive case of indefinite pronouns:
anybody's idea; everybody's problem; someone's car
D) An apostrophe without an s is added to form the possessive of plural nouns that end in s. Most plural nouns, of course, fit into this category.
babies' clothing; boys' teachers; doctors' patients
E) It also indicates the omission of letters or figures:
I've; can't, '48(1948); the class of '99 (1999)
F) It indicates the plural of letters and figures:
Let's begin with the B's.
Don't ever use the apostrophe to indicate plural!!!!
Wrong usage: The girl's are having English class.
Correct usage: The girls are having class.
Cambridge English First - Oral Exam Part 2
11 months ago