Relative clause

A relative clause (/ˈrelətɪv ˈklɔ:z/) is a type of subordinate clause.

English relative clauses are notoriously complicated, with entire book chapters often dedicated to them; consequently, this page can only give an introduction.

Overview

There are two types of relative clause in English; defining relative clauses (which are restrictive elements) and non-defining relative clauses (which are non-restrictive elements).

Type	Defining relative clause	Non-defining relative clause
Examples	This is the building where I work.	My sister, who is a teacher, lives in the UK.
Function	Either: To act as an adverbial to identify circumstances of an action or To act as an adjectival to describe a noun.	To add extra information
Notes	A comma does not separate the relative clause from the clause it is dependent upon.	Typically separated by commas.

Appropriacy

Relative clauses are far more common in written English, particularly formal written English, than in informal or spoken English.

Pedagogy

Relative clauses are typically introduced at about pre‑intermediate level, but their complexity means they are studied at intermediate level as well.

Since they are predominantly written grammar, it’s appropriate to focus on reading and writing these rather than speaking. Focusing on learning the rules may be a mistake; it may better to learn several examples and develop a natural feeling for the rules.

Whilst other European languages also use relative clauses, Chinese speakers may struggle because they don’t really use relative clauses in their language.