I’m leaving for Beijing.
3)be to+动词原形”表示按计划要发生的事或征求对方意见。例如:
Are we to go on with this work?
The boy is to go to school tomorrow.
4)“be about to+动词原形”表示即将发生的动作。例如:
We are about to leave.
4. 现在进行时的用法
1)现在进行时表示现在正在进行的动作,由“to be+现在分词”构成。例如:
What are you doing?
2)表示感觉,愿望和状态的某些动词,如have, be, hear, see, like等词一般不用进行时。
5. 过去进行时的用法
1)过去进行时表示过去某一时刻,某一阶段正进行的动作,由“was (were)+现在分词”构成。例如:
In 1980 he was studying in a university.
He was reading a novel when I came in.
6. 现在完成时的用法
现在完成时由“have+过去分词”构成。其使用有两种情况:
1)现在完成时所表示的动作在说话之前已完成,而对现在有影响。句中没有明显时间状语。例如:
He has gone to Fuyang . (说话人认为他不在该地)
He has been to Fuyang. (说话人认为他在该地)
)现在完成时所表示的动作开始于过去,持续到现在,也许还会持续下去。常用for和since表示一段时间的状语或so far, now, today, this week (month, year)等表示包括现在时间在内的状语。例如:
He has studied English for 5 years.
He has studied English since 1985.
Now I have finished the work.
注意:表示短暂时间动作的词,如:come, go, die, marry, buy等的完成时不能与for, since等表示一段时间的词连用。
3)现在完成时还可用在时间和条件状语从句中,表示将来某时完成的动作。例如:
I’ll go to your home when I have finished my homework.
If it has stopped snowing in the morning, we will go to the park.
7. 过去完成时的用法
)过去完成时由“had+过去分词” 构成,过去完成时的动作表示过去某一时刻或某一动作之前完成的动作状态。句中常用by, before, until, when等词引导的时间状语。例如:
By the end of last year we had built five new houses.
I had learnt 5000 words before I entered the university.
2)过去完成时的动词还可表示过去某一时刻之前发生的动作或状态持续到过去某个时间或持续下去。例如:
Before he slept, he had worked for 12 hours.
8)过去将来时的用法
过去将来时表示从过去的某时间看将要发生的动作或状态。过去将来时由“should或would+动词原形”构成。第一人称用should,其他人称用would.例如:
They were sure that they would succeed.
9)现在完成进行时的用法