Stephen, whose friends were from out of town, had a great time.

Find the adjective clause and copy/paste below.

whose friends were from out of town

"Whose friends were from out of town" is called an adjective clause because it functions as an adjective or modifier. Moreover, a clause is a group of related words that expresses a complete thought, one with a subject and a verb. This clause is considered a subordinating clause because it is used to complement the main clause or the sentence about Stephen.