2015年衛(wèi)生類(lèi)職稱(chēng)英語(yǔ)考試語(yǔ)法：時(shí)態(tài)

1)現(xiàn)在完成進(jìn)行時(shí)態(tài) (have/has been + -ing 分詞構(gòu)成): 動(dòng)作或狀態(tài)從過(guò)去某時(shí)開(kāi)始,繼續(xù)到現(xiàn)在,可能繼續(xù)下去,也可能剛剛結(jié)束.

I've been writing letters for an hour.

I've been sitting in the garden.

2)過(guò)去完成進(jìn)行時(shí)(由had been + ing分詞構(gòu)成): 過(guò)去某個(gè)時(shí)刻以前一直在進(jìn)行的動(dòng)作

I'd been working for some time when he called.

We had been waiting for her for two hours by the time she came.

3)將來(lái)完成進(jìn)行時(shí): 將來(lái)某個(gè)時(shí)刻以前一直在進(jìn)行的動(dòng)作.

By next summer, he will have been working here for twenty years.

In another month's time she'll have been studying here for three years.

4)將來(lái)完成時(shí)(由shall/will have + 過(guò)去分詞構(gòu)成): 將來(lái)某時(shí)已發(fā)生的事.

I shall have finished this one before lunch.

They'll have hit the year's target by the end of October.