Relative clauses let English identify a person or thing, add information about it, and connect ideas without starting a new sentence. Structures built with who, whom, whose, which, that, where, when and sometimes no overt relative word allow a noun phrase to carry its own miniature proposition: the student who solved the problem, the book that I borrowed, the town where she grew up, the report I sent yesterday.
The central distinction is not merely which relative pronoun to choose. It is whether the clause identifies the referent or merely adds supplementary information. Compare The students who revised passed with The students, who revised, passed. The punctuation-sized difference changes the set being described. In the first, the relative clause restricts which students are meant. In the second, the students are already identifiable and the clause adds a comment about them.
This volume explains how English relative clauses work: defining and non-defining relatives, relative pronouns, relative adverbs, subject and object gaps, omitted relatives, preposition placement, possessive whose, restrictive meaning, supplementary meaning, punctuation, reduced relatives, participial clauses, ambiguity, attachment and the reading errors caused when a modifier appears to describe the wrong noun.
This is SETC-HEW-018, Vol.018 of the How English Works series. Vol.015 owns broad clause-combining architecture. Vol.018 takes the relative-clause branch and develops its full reference-and-modification system.
Quick answer: what is a relative clause?
A relative clause modifies a noun or noun phrase by adding a proposition about it. The woman who called combines the noun woman with the proposition “the woman called.” The relative form links the clause back to the noun and leaves a corresponding gap inside the clause.
Defining relative clauses help identify which referent is meant and normally do not use commas. Non-defining relative clauses add supplementary information about an already identifiable referent and are normally set off with commas in writing.
Contents
- Relative clauses attach propositions to nouns
- Antecedents and relative gaps
- Defining relative clauses
- Non-defining relative clauses
- Who
- Whom
- Whose
- Which
- That
- Zero relative pronoun
- Where
- When
- Why
- Subject relatives
- Object relatives
- Prepositions in relative clauses
- Preposition stranding
- Formal preposition + whom/which
- Restrictive meaning
- Supplementary meaning
- Why commas change reference
- That versus which
- Relative clauses after proper names
- Relative clauses after pronouns
- Quantifier + of whom/which
- Sentential which
- Reduced relative clauses
- Present-participle relatives
- Past-participle relatives
- To-infinitive relatives
- Relative clause attachment
- Misplaced modifiers
- Ambiguous antecedents
- Heavy relative clauses
- End-weight
- Relative clauses in definitions
- Relative clauses in academic writing
- Relative clauses in narrative
- Relative clauses in speech
- Reading nested relatives
- The SETC Modifier Lock Test
- Maren: overpacked noun phrases
- Iona: wrong antecedent attachment
- Leonie: relative gaps in listening
- Tutor diagnosis
- Training cycle
- Common myths
- Worked relative-clause laboratory
- Frequently asked questions
- Research anchors
- Final synthesis
1. Relative clauses attach propositions to nouns
Start with two ideas: I met a teacher. The teacher works in Yishun. English can package them as I met a teacher who works in Yishun. The second proposition becomes a modifier inside the noun phrase.
This compression lets writers build precise reference without repeating the noun.
2. Antecedents and relative gaps
The noun modified by the relative clause is its antecedent. Inside the relative clause, one grammatical role corresponds to that antecedent. In the student who called, who occupies the subject role of called. In the student who I called, the student corresponds to the object gap.
Seeing the gap explains many relative-pronoun choices more reliably than memorising lists.
3. Defining relative clauses
A defining, restrictive or integrated relative clause helps identify which member or subset is intended: The books that are on the desk belong to Iona. The clause restricts the reference to books on the desk.
Remove the clause and the intended set may change. This is why defining relatives are part of the core noun phrase and normally appear without commas.
4. Non-defining relative clauses
A non-defining or supplementary relative clause adds information about a referent already identifiable: Iona’s laptop, which she bought last year, is already broken.
The laptop is identified by the possessive phrase before the relative clause begins. The relative clause adds a side comment rather than selecting which laptop is meant.
5. Who
Who commonly refers to people and can function as subject or, especially in conversational English, object: the teacher who called; the teacher who I met.
Its interpretation depends on the antecedent and the grammatical gap inside the relative clause.
6. Whom
Whom is the traditional object form and remains common after prepositions in formal styles: the person to whom I wrote. In everyday English, who or a zero relative is often preferred: the person who I wrote to; the person I wrote to.
Register matters more than treating one form as universally superior.
7. Whose
Whose marks a possessive relationship: the student whose essay won. It can also refer to organisations and things in standard English: a company whose profits increased.
The form lets a possessive slot inside the relative clause point back to the antecedent.
8. Which
Which commonly refers to non-human antecedents and can function as subject or object in relative clauses: the book which arrived; the book which I ordered.
It is also the standard choice in many non-defining relative clauses: The book, which arrived yesterday, is damaged.
9. That
That is common in defining relative clauses referring to people or things: the student that called, the book that I ordered. It is normally not used as the relative marker in ordinary non-defining clauses after a comma.
Usage guides differ in stylistic preferences between that and which in restrictive clauses, but real standard English permits patterns broader than one editorial house rule.
10. Zero relative pronoun
When the relative element is an object, English can often omit it: the book I ordered, the person we met.
Subject relatives normally cannot omit the relative marker: the person who called, not standard neutral the person called when the intended structure is a full finite relative clause.
11. Where
Where can introduce a relative clause linked to place: the house where she grew up. It often corresponds to a prepositional relationship such as the house in which she grew up.
12. When
When can link a relative clause to a time expression: the year when they met. Depending on style and meaning, English may also use in which or omit the relative marker in some time expressions.