What is a defining relative clause?
A defining relative clause gives essential information about a noun. Without it, we don't know which person, place, thing, or time is being referred to. There are no commas around the clause.
noun + relative pronoun + rest of clause
She's the teacher who helped me most.
This is the city where I was born.
Which relative pronoun to use
| The noun refers to… | Use | Example |
|---|
| a person | who / that | The woman who called left a message. |
| a thing or object | which / that | The phone which does everything is very expensive. |
| a place | where | The café where we met is closed now. |
| a time | when | There are times when I just want to switch off. |
💡 Remember: You can use that instead of who or which in defining relative clauses.
✓ The inventors that are creating new things… | ✓ The device that does everything…
Who, which, where and when in sentences
There are some inventors who are creating some pretty amusing things. (person)
The invention that is the most worrying so far is the 3-D printer. (thing)
I'm on a street where lots of young people hang out on Saturday evenings. (place)
If there's a time when people can make most of their own products, it's now. (time)
Common mistakes
⚠ Watch out:
✗ She's the person which called. → ✓ She's the person who called. (use who/that for people)
✗ That's the place who I grew up. → ✓ That's the place where I grew up.
✗ I remember the day which we met. → ✓ I remember the day when we met.
✗ She's the woman who she helped me. → ✓ She's the woman who helped me. (don't repeat the subject)