different tenses

past perfect tense is something happened BEFORE past tense

e,g " i had gone to bed before my mom came home.

I First went to bed..THEN my mom came home.

past perfect can show a specific time. an action that happened before another action in the past..it also use to make comparison between 2 events which happened in the past

past tense is a statement which only aim at telling you that whole event is entirely completed


hope can clear your doubt

Simple Past = Describe things happened in the past. 形容過往發生事情
e.g. I answered the questions yesterday. 昨天我解答那此問題

Past Perfect = Focus on the squential order / Explain things that already finished in the past 著重形容事件先後次序 / 交代過往已完成的事情
e.g. I had answered the same question for more than 10 times before you asked yesterday. 在你昨天發問之先，我已解答同一問題超過10次了
e.g. I had warned you not to go out without a map in Paris when we were on the plane. 當我們還在飛機上時，我已警告過在巴黎外出必須帶備地圖