Apostrophes (‘) are used to form contractions (can’t), to show possession (the essay’s argument), and to make a noun ending in s plural (performers’).

1. Showing letters left out of contractions.

  • Example 1: Sam can’t go to the mall because she didn’t do her homework.

  • Example 2: I would’ve done my homework, but I forgot my book at school.

Remember, for academic or formal writing, do not use contractions. Use a full phrase:

  • Informal: The dendrite isn’t a factor in this experiment.

  • Formal: The dendrite is not a factor in this experiment.

2. Using its and it’s.

When meaning it is, then use the contraction it’s. If you mean “belonging to it”, then use its.

  • Example 1: It’s raining today. (It is raining today.)

  • Example 2: The book is so old that its pages are falling out. (The book’s pages are falling out.)

3. Using whose and who’s.

The form who’s is a contraction that means who is.
The form whose is a possessive.

  • Example 1: Who’s there? (Who is there?)

  • Example 2: Whose dog is in my yard? (I want to know who owns that dog.)

4. Displaying a single noun as possessive.

  • Example 1: The teacher’s lesson plans were revised this year.

  • Example 2: The book’s pages are falling out.

When using an apostrophe to show that something belongs to or is owned by something else, it is not necessarily meant in the actual sense of owning. The book mentioned in Example 2 does not “own” its pages, but it does possess them.

Exception: If a singular noun ends in s, do not add another s to indicate possession. Instead, add an apostrophe after the singular noun in order to show possession.

  • Example 1: The weather is too hot for the circus’ animals to perform.

  • Example 2: The octopus’ tentacles are covered with tiny suction cups.

5. To display a plural noun ending in ‘s’ as possessive.

  • Example 1: The circus performers’ costumes were destroyed in the fire.

  • Example 2: The trees’ leaves are covering my entire lawn.

Because these nouns are plural and already end in s do not add another apostrophe s to show possession. Because of this, do not make any changes to the word itself, but add an apostrophe after the s to signify the noun as possessive.

Practice: Apostrophes

Rewrite the sentences below, inserting and deleting apostrophes where needed.

  1. (1) The boys books were left on the school stairs.

  2. (2) Johns mothers’ friend insists that I come to dinner.

  3. (3) Were going to my dads favorite restaurant: Wendys.

  4. (2) Its a shame that we don’t make cookies at my grandmothers house.

  5. (2) We we’re in Montreal when Josies car broke down.

  6. (1) My boss’s daughter works here now.

  7. (2) You shouldnt look through your sisters purse.

  8. (1) Were going to the mall tomorrow

  9. (2) There’re many tree’s in this forest.

  10. (3) Im suffering from writers block and cant think of any more apostrophe examples.