Relative clauses
Who, which, that, whose, where — add detail and combine ideas precisely.
Why it matters
Relative clauses let you pack information into one controlled sentence, which raises both Grammatical Range and Coherence. Errors with commas and pronouns are common, so accuracy matters as much as use.
The rules
Defining clauses identify which one — no commas; 'that' is allowed.
Students who work part-time often sleep less.
Non-defining clauses add extra information — commas; never 'that'.
Tokyo, which has 14 million residents, is very safe.
Use whose for possession, where for places, when for times.
Countries whose populations are ageing face pension pressure.
'Which' can refer to a whole previous idea.
Prices rose, which reduced demand.
Model sentences
- Workers whose jobs can be automated are the most vulnerable to economic change.
- Finland, which spends less on schooling than many countries, consistently achieves strong results.
- Consumption fell by a third, which suggests the campaign was effective.
Common mistakes
Incorrect: London, that is the capital, is expensive.
Correct: London, which is the capital, is expensive.
Non-defining clauses can't use 'that'.
Incorrect: The people which live there are friendly.
Correct: The people who live there are friendly.
'Who' for people.
Incorrect: This is the town where I was born there.
Correct: This is the town where I was born.
Don't repeat the place.
Band tip
Check yourself
Combine: 'Some children use tablets daily. They often have shorter attention spans.'
Children who use tablets daily often have shorter attention spans.
My brother, ___ lives in Kumasi, is a nurse.
who
The company, ___ profits doubled, hired 200 staff.
whose