The apostrophe probably causes more grief than all of the other punctuation marks put together! The problem nearly always seems to stem from not understanding that the apostrophe has two very different (and very important) uses in English: possession and contractions.
The apostrophe in contractions.
The most common use of apostrophes in English is for contractions, where a noun or pronoun and a verb combine. Remember that the apostrophe is often replacing a letter that has been dropped. It is placed where the missing letter would be in that case.
|Using “not”||is not, has not, had not, did not, would not, can not||isn’t, hasn’t, hadn’t, didn’t, wouldn’t, can’t|
|Using “is”||she is, there is, he is, it is, Mary is, Jim is, Germany is, who is||she’s, there’s, he’s, it’s, Mary’s, Jim’s, Germany’s, who’s|
|Using “am”||I am||I’m|
|Using “will”||I will, you will, she will, we will, they will||I’ll, you’ll, she’ll, we’ll, they’ll|
|Using “would”||I would, you would, he would, we would, they would||I’d, you’d, he’d, we’d, they’d|
|Using “have”||I have, you have, we have, they have||I’ve, you’ve, we’ve, they’ve|
|Using “are”||you are, they are, we are||you’re, they’re, we’re|
People, even native English speakers, often mistake its and it’s, you’re and your, who’s and whose, and they’re, their and there. See below for the difference.
- It’s a nice day outside. (contraction)
- The cat is dirty. Its fur is matted. (possession)
- You’re not supposed to be here. (contraction)
- This is your book. (possession)
- Who’s at the door? (contraction)
- Whose shoes are these? (possession)
- They’re not here yet. (contraction)
- Their car is red. (possession)
- His car is over there. (location)
The possessive apostrophe.
In most cases you simply need to add ‘s to a noun to show possession
- a ship’s captain
- a doctor’s patient
- a car’s engine
- Ibrahim’s coat
- Mirianna’s book
Plural nouns that do not end in s also follow this rule:
- the children’s room
- the men’s work
- the women’s club
Ordinary (or common) nouns that end in s, both singular and plural, show possession simply by adding an apostrophe after the s.
- the bus’ wheel
- the babies’ crying
- the ladies’ tennis club
- the teachers’ journal
Proper nouns (names of people, cities, countries) that end in s can form the possessive either by adding the apostrophe + s or simply adding the apostrophe. Today both forms are considered correct (Jones’s or Jones’), and many large organisations now drop the apostrophe completely (e.g. Barclays Bank, Missing Persons Bureau) when publishing their name.