謂語動詞構成：I/we/you/they have worked; he/she/it has worked

(1) 表示過去某一時刻發生，且延續到現在的動作或狀態，這種情況常與表示一段的時間狀語連用

We have lived here since last October. 自從去年十月份我們就一直住在這兒。

She has studied English for 5 years. 她學英語已有5年之久

(2) 表示某個已經發生且對現在造成影響或結果的動作，這種情況常不與任何時間狀語連用

I’m sorry I have lost my key. I can’t open the door.

對不起，我把鑰匙弄丟了.門開不了了.

She has left. If you want to see her, you’ll have to come tomorrow.

她已經走了.如果你想見她的話，你得明天再來一趟.