現在完成式 have/has+Vp.p.
從過去某個時間點開始並持續進行到現在
常與for、since使用
for後面+一段時間 for two months、for a long time
<例>Coco has worked at the same department store for ten years.
since後面+一個具體時間 since2002、since last week
<例>She has been in class since nine o'clock this morning.
have been to已經回來了
have gone to 去了還沒回來
過去完成式 had+Vp.p.
We were not able to get a hotel room because we had not booked in advance
沒有預定為先發生，所以為過去完成式
I had gotten on the bus when I received his phone call.
我接到他的電話時，我已經搭上那班公車了