An essential relative clause provides necessary, defining information about the noun. On the other hand, non‐ essential relative clauses provide additional, non‐necessary information about the noun.

Relative clauses are used to give additional information about a noun, such as a person, place or thing. Relative pronouns introduce a relative clause. They include who for people, that and which for ...

Non-defining relative clauses are a speaker's friend. Dan teaches us five ways to use them in this bite-sized video.