The rule, as people use it
To say something belongs to someone, add 's to the owner: Priya's phone, my brother's car, the teacher's desk. When the owner is a plural that already ends in -s, you add only the apostrophe: my parents' house, the students' books. Plurals that don't end in -s, like children or people, take 's as normal: the children's room.
Here's the good news for speaking: "my brother's car" and "my brothers' car" sound exactly the same. The apostrophe is a spelling problem, not a speaking one. What you do need to say is the "s" sound itself. "This is Oliver car" is the common learner mistake, and it makes the listener work harder.
The other thing to know is that English speakers rarely say "the car of my brother". It's correct, but it sounds like a textbook. For people and animals, use 's. For things and places, "of" is still normal: the end of the movie, the top of the page.
Examples
Tap a sentence to hear it. Say it after the voice.
Fill the gap
Type the missing words, then check. The full sentence plays when you get it.
- 1
This is (Oliver) car.
- 2
We had dinner at my (parents) house.
- 3
The (children) toys are everywhere.
- 4
Is this (who) coat?
- 5
That isn't my pen. It's (Wei).
- 6
My (sister) apartment is in Chicago.
- 7
I can't find the start (of / 's) the file.
- 8
The (teacher) desk is near the window.
Practice · 3 min
Think of five people you know and one thing each of them owns. Say a sentence for each out loud: "My mom's car is red." "Rohan's dog is huge." Then say two sentences with a plural owner ending in -s, like "my neighbors' garden", and check that you wrote the apostrophe after the s.
Say it today
Use it once in a real conversation before tomorrow. Out loud counts, even to yourself.