A relative clause is a clause that modifies a noun. A relative clause is often called an adjective clause because it functions as an adjective in a sentence.
A relative clause is introduced by a relative pronoun, a relative adverb, or a zero relative.
Relative pronouns are <em>which, that, who, whom, whose. </em>
<em>e.g. </em>She is the person <em> </em><u><em>to whom I have sent the letter</em></u><em>.</em>
Relative adverbs are <em>where, when, why</em>.
<em>e.g. </em>I will always remember<em> </em>the day<em> </em><u><em>when I met her</em></u><em>.</em>
A zero relative is occuring when we omit the relative pronoun.
<em>e.g. </em>The man <u><em>you hired</em></u> is not very responsible. (the relative pronoun is left out because it is the object of the relative clause)