English Grammar Lab

← B1

Who, which and that

You will be able to Connect information using defining relative clauses.

Explanation

Use who for people, which for things, and that for people or things in many defining relative clauses.

Examples

Detailed course

Understand the grammar point

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Detailed explanation

This lesson focuses on who, which and that. The structure helps learners organise connected speech and writing, and it should always be interpreted as part of a complete message rather than as an isolated formula. Before selecting a form, identify the subject, time reference, clause relationship, and the information that receives emphasis.

Formation is central. Use who for people, which for things, and that for people or things in many defining clauses. Omit the relative pronoun only when it is the object, not the subject. Build the sentence in stages: identify the grammatical subject, choose the auxiliary or main verb form, and complete the clause in normal English word order. In negatives and questions, check whether the structure supplies its own auxiliary or requires another one.

The pattern can help users explain reasons and results, report experience and information, and choose between related grammar patterns. These purposes may overlap, so context decides which interpretation is natural. Time expressions, determiners, linking words, and punctuation often provide evidence for the correct choice.

A useful contrast prevents overgeneralisation. Non-defining relative clauses add extra information, use commas, and do not normally use that. Ask how the nearest alternative would change time, certainty, focus, politeness, or register. A grammatically possible sentence may still communicate the wrong relationship if that contrast is ignored.

The guided examples are complete messages. Notice how the target structure agrees with its subject and how the surrounding vocabulary makes the intended meaning clear. When producing a new example, preserve the relationship between form and meaning while changing the people, place, and lexical details.

A reliable self-check is to paraphrase the sentence in simpler language. If the paraphrase changes the time relationship, degree of certainty, or focus, review the original form. Compare the sentence with the common mistakes and explain why the corrected version is preferable.

In connected speech and writing, the structure also contributes to cohesion. It guides the reader through background information, main events, causes, qualifications, and results. Clause order and connector choice can therefore affect interpretation even when every individual word is correct.

How to form it

Use who for people, which for things, and that for people or things in many defining clauses. Omit the relative pronoun only when it is the object, not the subject.

Use the structure to organise connected speech and writing.

Use the structure to explain reasons and results.

Use the structure to report experience and information.

Use the structure to choose between related grammar patterns.

Non-defining relative clauses add extra information, use commas, and do not normally use that.

Guided examples

The volunteer who manages the desk speaks three languages.

Who introduces information about a person, the volunteer.

The map that shows the emergency exits is beside the door.

That introduces information about a thing, the map, and could also be replaced by which.

The room which contains the computers is upstairs.

Which introduces information about a thing, the room.

The student whom we interviewed described the project clearly.

Whom refers to a person and is the object of interviewed, not the subject.

This is the form that you need to complete.

That is the object of complete here, so it could also be left out: the form you need to complete.

People who require assistance can use the side entrance.

Who introduces information about people, the subject of require.

Common mistakes

Not: The volunteer which manages the desk speaks three languages.

Use: The volunteer who manages the desk speaks three languages.

Volunteer is a person, so the clause needs who, not which.

Not: The map who shows the emergency exits is beside the door.

Use: The map that shows the emergency exits is beside the door.

Map is a thing, so the clause needs that or which, not who.

Not: The room who contains the computers is upstairs.

Use: The room which contains the computers is upstairs.

Room is a thing, so the clause needs which or that, not who.

Not: The student who we interviewed described the project clearly.

Use: The student whom we interviewed described the project clearly.

The student is the object of interviewed here, so the more formal whom fits this pattern; who is used mainly as the subject.

Before you practise

  • Identify the communicative purpose.
  • Check the subject and required verb or auxiliary.
  • Confirm the time reference and clause order.
  • Compare the sentence with the nearest alternative.
  • Read the complete sentence and verify the meaning.

Reading text

People at the Learning Centre

About 263 words

Youssef and new visitors gathered at the evening learning centre to find the right rooms and advisers. The main difficulty was clear: the centre is busy and several people need help. They spread badges, laptops, and interview forms across the table and agreed to work through the facts one by one. The tutor who teaches writing is upstairs. That first detail changed the mood in the room because it gave the group something concrete to discuss. This is the room where interviews happen. After that, the group compared names, times, and places instead of guessing. The laptop that prints badges is slow tonight. A short disagreement followed, but it helped them notice a missing detail. I need the adviser who speaks Arabic. When the final note was added, the plan felt realistic and easy to explain. Before they left the evening learning centre, the result was clear: each visitor reaches the correct table. Youssef and new visitors return to badges, laptops, and interview forms because each item helps with the task. The notes show why the centre is busy and several people need help. The group checks the time, the place, and the next decision before moving on. No one rushes, because a small error would change the outcome. The work stays connected to the evening learning centre, where the problem first became visible. By the end, the result is clear: each visitor reaches the correct table. Later, the written record helps the group explain the decision without adding new claims. The strongest clue comes from the materials, not from anyone's memory alone.

Reading comprehension

  1. Who is involved in the reading?

    Show answer

    Youssef and new visitors

  2. Where does the reading take place?

    Show answer

    the evening learning centre

  3. What task are the people trying to complete?

    Show answer

    find the right rooms and advisers

  4. What problem makes the task less simple?

    Show answer

    the centre is busy and several people need help

  5. How does the reading end?

    Show answer

    each visitor reaches the correct table

Grammar in the text

  1. The tutor who teaches writing is upstairs.

    Who introduces information about a person, the tutor.

  2. This is the room where interviews happen.

    Where introduces information about a place, the room.

  3. The laptop that prints badges is slow tonight.

    That introduces information about a thing, the laptop.

  4. I need the adviser who speaks Arabic.

    Who introduces information about a person, the adviser.

Key point

Use this pattern when the meaning needs it in the reading: who/which/that/where + clause. In short, relative clauses identify or add information about people, places, and things. Example: "The tutor who teaches writing is upstairs."

Practice

  1. Complete the sentence from the same situation: "The tutor who teaches writing ____ upstairs."

    Show answer

    The tutor who teaches writing is upstairs.

  2. Complete the sentence from the same situation: "This ____ the room where interviews happen."

    Show answer

    This is the room where interviews happen.

  3. Complete the sentence from the same situation: "The laptop that prints badges ____ slow tonight."

    Show answer

    The laptop that prints badges is slow tonight.

  4. Complete the sentence from the same situation: "I need the adviser ____ speaks Arabic."

    Show answer

    I need the adviser who speaks Arabic.

Listening practice

Watch a TEDx talk

“Your body language may shape who you are” — Amy Cuddy (TED). Listen for clear, natural English and pick up new vocabulary while you review this grammar point.

Check your understanding

According to Amy Cuddy, what happened to participants who held a high-power pose for two minutes?

Check your understanding

What is Amy Cuddy's key piece of advice, in her own words?

Practice

Choose the correct answer. The man ___ called you is my uncle.

Practice

Choose the correct answer. This is the laptop ___ I bought.

Practice

Choose the correct answer. The student ___ won the prize is in my class.

Written practice

Produce the answer yourself. Capitalisation and final punctuation do not affect validation, but the grammar and word order must be correct.

Word ordering

Written practice

Put the words in the correct order.

the colleague / who / fixed / the server / on Monday / is / here