Y05W17GR Relative clauses 1 (who/which/that)

Relative clauses 1 (who/which/that)

Writing becomes more informative when extra detail about a noun is added inside the same sentence. A relative clause does exactly this — it sits inside or at the end of a sentence and tells the reader more about a specific person, animal or thing. Using who, which and that correctly keeps these added details clear and connected.

You’ll learn
  • What a relative clause is and how it connects to a noun
  • When to use who, which and that as relative pronouns
  • How to add a relative clause without losing the clarity of the sentence
Core ideas
  • Relative clause — a group of words beginning with who, which or that, which adds information about a noun already named in the sentence.
  • Relative pronoun — the word (who, which or that) that introduces the relative clause and refers back to the noun.
  • Who — used for people. For example, the student who forgot her bag.
  • Which — used for animals and things. For example, the bird which migrates south every winter.
  • That — used for people, animals or things in everyday writing. For example, the animal that uses the stars to navigate.

How it works

1Using who for people

The relative pronoun who introduces a clause that gives extra information about a person. Choosing who for people makes the sentence precise and natural.

  • Who connects directly to the noun it describes. For example, The student who sits at the front won the prize — who sits at the front tells us exactly which student.
  • Position — the relative clause follows the noun it describes, usually immediately after it. For example, The teacher who coached us last year has moved schools.
  • Removing the clause — the main sentence still makes sense without the relative clause. For example, The student won the prize still works on its own.

2Using which for animals and things

The relative pronoun which introduces a clause about an animal or thing. It is the correct choice when the noun is not a person.

  • Which follows the noun it describes and gives extra detail. For example, The map which hung on the wall was very old — which hung on the wall identifies the specific map.
  • Animals — which is used when referring to an animal as a thing. For example, The whale which swam past the boat was enormous.

3Using that for people, animals or things

The relative pronoun that is flexible — it works with people, animals and things in everyday and informal writing. Understanding when that fits helps writers choose confidently.

  • That can replace who or which in many sentences. For example, The dog that barked all night kept everyone awake.
  • Everyday writing — that sounds natural in less formal contexts. For example, The tool that guides birds during migration is called a magnetic sense.
  • Not interchangeable in all cases — which is preferred when the clause adds optional extra information, rather than essential identification.

See it in action

Missing relative clause — extra detail needed

Before

The bird flew south for winter.

After ✓

The bird which uses the stars to navigate flew south for winter.

Adding which uses the stars to navigate tells the reader exactly which kind of bird is being described, making the sentence more informative.

Wrong relative pronoun used for a person

Before

The scientist which discovered this ability made an important finding.

After ✓

The scientist who discovered this ability made an important finding.

Who is the correct pronoun for a person — which is reserved for animals and things.

Relative clause added to expand a simple sentence

Before

The dog followed the trail home.

After ✓

The dog that had lost its way followed the trail home.

Adding that had lost its way gives the reader important context about which dog is being described.

Quick check
  • A relative clause begins with who, which or that and adds detail about a noun.
  • Use who for people, which for animals and things, and that for any of these in everyday writing.
  • The relative clause sits directly after the noun it describes.
  • Removing the relative clause should leave the main sentence still complete and clear.
  • Choosing the right relative pronoun keeps writing precise and readable.
Metalanguage
  • relative clause(n.) a clause beginning with who, which or that that gives extra information about a noun — in The student who scored the goal celebrated, the relative clause is who scored the goal.
  • relative pronoun(n.) the word that introduces a relative clause and refers back to the noun — who, which and that are the three main relative pronouns at this level.