例： Where did your brother study before he joined the army?
過去完成時可表示截止過去某一時間動作的總或動作的結(jié)束。
例：By the end of last month. We had reviewed four books
By eight o`clock, he had finished his homework.
與這個時態(tài)連用的時間狀語常有：
by 1985, by eight o`clock, by then, by the end of last month, by the time when, when, as soon as, before 等連詞引導(dǎo)的時間狀語從句，表示主句動作結(jié)束的時間。
現(xiàn)在進(jìn)行時主要用于：
表示現(xiàn)在或現(xiàn)階段正在進(jìn)行的動作。
例： Listen, someone is crying.
What are you doing these days?
代替一般現(xiàn)在時，表示經(jīng)常性動作或狀態(tài)，而含有某種感情色彩。
例： How are you feeling today?
你今天感覺怎樣?(顯得親切)
He is doing well in his lessons.
他的功課很好。(贊揚)
You are always boasting.
你老愛吹牛。(厭煩)
動詞 go, come, leave, arrive 等表將要發(fā)生的動作時。
例：They are leaving for Shanghai.
與這種時態(tài)連用的時間狀語常有：
now, these days, recently, this week 等。