|John had gone out||when I arrived in the office.|
|I had saved my document||before the computer crashed.|
|When they arrived||we had already started cooking.|
|He was very tired||because he hadn't slept well.|
英語中的過去完成式是由兩個要素形成：動詞 have 的過去式 had + 主要動詞的過去分詞。
過去完成式，以 to decide 為例：
|I had decided.||I hadn't decided.||Had I decided?|
|You had decided.||You hadn't decided.||Had you decided?|
|She had decided.||She hadn't decided.||Had she decided?|
|We had decided.||We hadn't decided.||Had we decided?|
|They had decided.||They hadn't decided.||Had they decided?|
- The train had just left when I arrived at the station.
- She had just left the room when the police arrived.
- I had just put the washing out when it started to rain.