Simple past, Past Continuous, and Past Perfect – …
Subject + helping verb + (event 1) main verb (past participle form) + link + object + (event 2) main verb (in simple past form) Example: The sun had set before the party started. Note that here two events are described. Event 1: The sun set (in past perfect tense) Event 2: The party began (in simple past tense) Linking these events: before.