Apostrophes in English are used for possession and contraction. They are not used to form plurals.

POSSESSION :

Apostrophes are used to indicate possession in nouns (but not in pronouns: hers, ours, theirs….).

  • The girl‘s bicycle.
  • The bicycle is hers (not her’s).

To show possession, ‘s is added to a singular noun (even if the noun ends in ‘s’).

  • John‘s car.
  • James‘s guitar.

To show possession in a plural noun, the apostrophe is added after the plural s.

  • My parents’ house is near the coast.
  • Visitors are not allowed into the students’ rooms.
  • Witches’ hats are pointed.

If the word is plural but does not end in s, simply add an ‘s for possession.

  • The children’s playground is beside the school.

CONTRACTION :

Apostrophes are used to indicate missing letters in contractions. For example:

  • He’s is a contracted form of he is.
  • It’s is a contracted form of it is.
  • Its is a possessive pronoun like ‘my’, ‘his’, ‘her’, etc.
    • The dog was chewing its toy.
      It’s (it is) its toy so that’s (that is) ok.
  • Who’s is a contracted form of who is.
    • Who’s (who is) the owner of the red car?
    • Whose car was damaged during the storm?