Relative clauses add information about a noun using pronouns like who, which, that, whose, and where. They can be defining (essential to the meaning) or non-defining (extra information set off by commas). Getting the pronoun and comma usage right is a key advanced skill.
3 subtopics — pick one to start practising
Relative Pronouns
Use who or that for people, which or that for things, whose for possession, where for places, and when for times. In defining clauses, that can replace who/which. In non-defining clauses (with commas), that is not used — you must use who or which. When the pronoun is the object of the clause, it can be omitted in defining clauses: "The book (that) I read was excellent."
Defining vs. Non-Defining Clauses
A defining relative clause identifies which specific person or thing you mean. It is essential to the meaning and has no commas: "The students who passed can move on." A non-defining clause adds extra information about a noun that is already specific. It is set off by commas and can be removed without changing the core meaning: "My sister, who lives in Toronto, is visiting next week."
Combining Sentences with Relative Clauses
Relative clauses are a key tool for joining two sentences elegantly. "I have a colleague. She speaks five languages." → "I have a colleague who speaks five languages." Find the noun that appears in both sentences, replace it with the appropriate relative pronoun, and embed the second clause into the first.