Relative Clauses

In person + who + verb, who itself is the subject, the performer of the action. In The nurse who called me, who means the nurse: the nurse made the call.

Do not add he, she or they after subject who. English does not repeat the same person twice in this position: who works, not who she works. The verb agrees with the person before who: a student who studies, students who study.

Who can be the recipient rather than the performer of an action. In The colleague who I called, I is the subject of called, while who refers to the person I called.

In a defining clause, a description that helps identify the person, object who can often be omitted: The colleague I called. If who itself performs the action, keep it in this full pattern: The colleague who called me.

In formal style, object who can be replaced by whom. Who is normal in neutral conversation, and a preposition can remain at the end: the person who I spoke to.

In the basic contrast, who refers to people and which to things. We therefore say the woman who called but the phone which rang. This is a useful guide, not a claim that who can never refer to a beloved animal or a group of people in wider English usage.

That is possible in a defining clause about a person: the woman that called. If an exercise specifically asks for who, use it; a correct that in another situation does not become an error.

Which for an individual person in a standard construction such as the man which called is an error. Which naturally introduces information about an object instead.

A defining relative clause contains information needed for identification. In The nurse who works nights can help you, who works nights distinguishes the relevant nurse from others.

In neutral writing, do not set this clause off with commas. It comes immediately after the word it describes, not in an arbitrary position at the end of the sentence.

It is in a defining clause that object who can be omitted when the clause already has its own subject: the nurse who I called or the nurse I called.

When a person is already clearly identified, who can add information that is supplementary rather than needed for identification: Marta, who works at a hospital, is visiting. In writing, set this clause off with commas on both sides if the sentence continues.

In a non-defining clause, do not omit the relative pronoun or use that. For a person, use who, or the more formal whom as an object. This lesson gives the basic boundary; a detailed treatment of all non-defining clauses belongs to a higher level.

Without commas, the description helps identify the brother: My brother who lives in Lviv. With commas, My brother, who lives in Lviv, presents his residence as an additional fact. Commas alone do not prove how many brothers the speaker has.

To build a sentence, first name the person, add the who-clause immediately, then complete the main message. Check who performs the action inside the subordinate clause: if it is who, the verb follows directly; if I, we, Maya or someone else performs it, who is the object.

Do not try to insert who into every sentence about a person. It is needed when a clause describes a noun inside a larger sentence. The separate Who called? is a question, not a relative clause.

You may use real or invented people in your examples. Check meaning, the position of who, the absence of a redundant pronoun, verb agreement and commas when the information is genuinely supplementary.

Which usually refers to an inanimate object, an animal or an abstract thing: a phone, a dog, a plan, some advice. Who is the typical choice for a person. First identify the noun before the relative clause, then choose the pronoun.

In a defining description that identifies the thing being discussed, that can often replace which: The phone that I bought works well. Both versions are correct.

In The app which sends reminders is free, which is the subject performing sends. The relative clause's verb follows it directly. Do not add another subject, it: which already represents the app within this clause.

Do not omit which when it is the subject. The app sends reminders is free lacks a grammatical connection between app and its description. A useful clue is that which is usually the subject when a verb follows it directly.

In The film which we watched was funny, we is the relative clause's subject and which is the object of watched: we watched the film. A separate subject, we, therefore follows which.

In a defining clause, this object which can often be omitted: The film we watched was funny. Both versions are grammatical. If which remains, do not repeat the object with it: use which we watched, not which we watched it.

A defining relative clause identifies exactly which thing is meant. In Use the printer which has a green label, the description selects one printer from several, so there are no separating commas. In such a clause, that may replace which, and object which can sometimes be omitted.

A non-defining relative clause adds information about a thing already clearly identified. In OfficePro, which is free, can open the file, the name OfficePro already identifies the application. Enclose the extra information in commas; do not omit which or replace it with that. These commas convey meaning rather than serving as optional decoration.

First name the thing. Then check that the relative clause is close to the intended noun, does not repeat it with it, and has a complete structure. If which performs the action, a verb follows it. If another person performs the action, a separate subject follows which.

Next decide the purpose: does the description select one thing from several or merely add detail about something known? That determines the commas. In an everyday defining clause, that or omitted object which may sound natural, but a response without which does not fulfil an exercise explicitly requiring which.

Which can also refer to an entire preceding clause: The train was late, which was annoying. This is a genuine use, but it is outside this rule's narrow A2 focus and is not assessed here.

In defining relative clauses, that can replace who for people and which for things or animals. The driver that waited and The bus that stopped therefore have the same structure.

Who for a person and which for a thing often remain entirely grammatical alternatives. This rule aims to teach appropriate that usage, rather than label other standard options incorrect.

That is particularly common in everyday and informal language. In a more formal text, an author may choose who or which, but this is a style choice in a defining clause, rather than a universal ban on that.

If the person or thing itself performs the action in the relative clause, that is its subject. The verb follows that directly: the colleague that speaks Spanish, the bus that stops here.

You cannot simply remove this that because the clause would have no subject. Do not add a second subject he, she or it either: that already performs that role.

If that is followed by a separate subject, that is the object: the book that you lent me. You performs lent, while book is what was lent.

In a defining relative clause, object that can be kept or omitted: the book that you lent me and the book you lent me. Both are grammatical. If that is kept, do not repeat the object with it, him or her.

A non-defining relative clause adds incidental information about a person or thing already identified. Writing sets off this clause with commas; standard English does not use that here.

Compare The designer that works downstairs can help, which identifies the designer, with Maya, who works downstairs, can help. Maya’s name already identifies the person, and the relative clause only adds information. The second sentence needs who, rather than that.

A defining relative clause usually immediately follows the noun it identifies. This makes it easy to connect the form with that I completed, or the assistant with that speaks Polish.

Relative that replaces the subject or object within the clause. Do not duplicate that same element: not that she works or that I completed it. The minimal correction is to remove the unnecessary pronoun.

First name the person or thing, then add a characteristic that helps the listener choose the intended one: the room that has a projector, the file that you sent, the volunteer that speaks Spanish.

After building the sentence, quickly check who performs the action in the relative clause. If it is that, do not omit it. If a separate subject follows that, that is an object and can be absent. Also check that this really identifies something without commas, rather than adding extra information.