A clause that begins with a relative pronoun is a?

A clause that begins with a relative pronoun is called a relative clause.

Here's a breakdown:

* Clause: A group of words containing a subject and a verb.

* Relative Pronoun: A pronoun (who, whom, whose, which, that) that connects a relative clause to its antecedent (the noun or pronoun the clause modifies).

Example:

* The dog that barked at me is friendly.

In this sentence:

* "The dog" is the antecedent.

* "that barked at me" is the relative clause.

* "that" is the relative pronoun, connecting the clause to "dog".

Relative clauses can be restrictive (essential to understanding the sentence's meaning) or non-restrictive (providing extra information).

Let me know if you'd like more examples or explanations!