Apostrophes (‘) have two uses.

They show that a letter, or letters, has been left out from a word in a contraction:

  • It’s not ready yet.
    (it is)
  • We should’ve stayed outside.
    (should have)

They show possession:

  • The dog’s paws are dirty.
    (The dog has paws.)
  • Please show me the children’s room.
    (The children have a room.)

Apostrophes are not used to show plurals.