"Had started" is a phrase used in the past perfect tense, indicating that an action began before another action or time in the past. For example, if someone says, "She had started her homework before dinner," it means the homework was initiated prior to the dinner time. This construction helps clarify the sequence of events. It emphasizes that one action was completed before another took place. In writing or conversation, using "had started" can provide context and enhance understanding of timelines, especially when discussing events related to schoolwork, projects, or daily activities.