select the entire correct adjective clause for the sentence below. then select which word is modified by the clause.
those whose tickets have been punched may enter the park.
adjective clause:
those whose tickets
have been punched
enter the park
whose tickets have been punched
word modified by clause:
those
tickets
park

Adjective clauses modify the noun or the pronoun in the sentence's main clause. The first thing to do is to identify the two clauses in the sentence.

First clause: Those may enter the park (the main clause)
Second clause: whose tickets have been punched (the subordinate clause)

Since adjective clauses generally start with a relative pronoun, it is clear that the second clause is the adjective clause. The relative pronoun is "which". Another clue is that adjective clauses are always the subordinate clause. It modifies the pronoun those.