Need help combinig these sentences .I havee to make dependent clauses.The heavy door wouldnt budge.we tried to close it.

Dependent clauses will have introductory words that are easy to identify:

when, if, because, since, although, if, and others (to make adverb clauses)

who, whom, whose, which, that - relative pronouns (to make adjective clauses)

Try starting the revised sentence with "When" and then add the second clause and finally the first clause. What do you get?