Using the apostrophe

When using the apostrophe, many non-native and native speakers have difficulty in achieving its accurate and appropriate placement, as the apostrophe has a range of functions in the English language. Some uses like contractions (I can’t help / I’ll help) are straightforward, while others such as possession (The teacher’s meeting vs the teachers’ meeting) are more challenging. This post will help identify the range of circumstances where using the apostrophe is appropriate, and where so, how this can be achieved.

Contractions (missing letters)

Using the apostrophe

We use the apostrophe to show that letters have been removed in informal contexts. These contractions happen with:

  1. The auxiliary verbs be (is/am/are) and have (have/has/had): He’s an engineer (He is); I’m exhausted (I am); They’re late for dinner (They are); They’ve finished (They have); She’s got a new car (She has); He’d already left (He had).
  2. The negative adverb not: I don’t understand (I do not); We can’t help (We cannot); You mustn’t complain (You must not); They won’t be here until 7pm (They will not).
  3. The modal auxiliaries will and would: I’ll be there at 5pm (I will); She’d always make Sunday dinner for the family (She would).

* Remember that -‘s could be a contraction of the verbs ‘be’ or ‘have’ in their third person singular form (is) or (has). Therefore, further contextual clues are needed to understand what the full verb actually is: She’s a new teacher could mean either that she is a new a teacher or that she has a new teacher.

** Also keep in mind that many negative contractions allow you several options for how to present them: He isn’t tired vs He’s not tired; She’ll not be at the party vs She won’t be at the party; They’d not like it vs They wouldn’t like it.


We use the apostrophe before and after the final -s in nouns to show possession or ownership:

  1. After singular nouns add -‘s: This is the student’s assignment (one student); Our friend’s father (one friend).
  2. After plural nouns ending in -s, add the apostrophe only: The students’ classroom (for all the students); Our friends’ house (all of them are our friends).
  3. After irregular plural nouns, add -‘s: Here are the men’s changing rooms; It was the people’s choice.

* Note that some singular proper nouns end in a final -s, such as James or Mrs Evans. Here you would add -‘s for possession: That is James’s son; Mrs Evans’s daughter got into Oxford University. However, some reference books also promote as correct usage without adding the -‘s: That is James’ son; Mrs Evans’ daughter got into Oxford University.

Special cases

There are some other less common cases where apostrophes are used:

  1. To introduce some binomials: There are lots of if’s and but’s.
  2. To pluralise letters: Your b’s look like d’s when you write.
  3. To pluralise numbers: The 1950’s were a period of relative peace (although without the apostrophe is also acceptable: 1950s).