Relative pronouns introduce relative clauses that clarify or specify the antecedent. For example, in "Trees, which are plants, need sunlight to grow," the word "which" is a relative pronoun.
Relative pronouns tie in relative clauses that clarify or specify the subject.
For example:
He who laughs last is the slowest to get the joke.
In the preceding sentence, "who" is a relative pronoun that introduces the relative clause "who laughs last"—which helps narrow down and define the antecedent noun phrase "He".
The main relative pronouns are:
- That
- Which / Whichever
- Who / Whom / Whoever / Whomever
- Whose
But When, Where, and Why may also be called relative pronouns.
And What can be one too.
Additional References:
