An adjective clause is a dependent clause used as an adjective within a sentence. An adjective clause usually begins with a relative pronoun or a relative adverb. The sandwich that you ate had a fly in it

that you ate.

Explanation:

An adjective clause can be defined as a dependent clause that has a subject and a verb in it. This clause does not convey the meaning as a whole but works to modify the noun or pronoun in a sentence. Usually, an adjective clause begins with when, that, where, which, etc.

In the given sentence, the adjective clause is "that you ate."

The subject is 'you' and verb 'ate.'

It is modifying the noun 'sandwich' in the sentence as it is describing the sandwich.