Look! The race is about to start. 瞧！比赛就要开始了。

注：该结构通常不与具体的时间状语连用。

3."will [shall] + 动词"与"be going to + 动词"。两者均可表示将来的打算或意图，有时可换用，有时不可换用。不可换用的情况主要是：若强调某个意图是经过事先考虑好的，用be going to; 若表示某个意图没有经过事先考虑，而是在说话的时候临时想到的，则用will。比较：

"Mary is in hospital. " "Oh, really? I didn't know. I'll go and visit her. " "玛丽住院了" "啊，真的吗？我还不知道。我要去看看她。"（临时想法，不能用be going to）

"Mary is in hospital. " "Yes, I know. I'm going to visit her tomorrow. " "玛丽住院了。" "是的，我知道。我打算明天去看看她。"（事先考虑好的意图，不能用will）

另外，若有迹象表明要发生某事，用be going to，而不用will。如：

Look at those black clouds. It's going to rain. 看那些乌云。要下雨了。

四、现在完成时的用法

1.表示过去发生的动作对现在所造成的影响或表示从过去某一时刻开始一直延续到现在的动作或状态。如：

Have you considered going abroad to study? 你有没有考虑过出国留学？

The storm has lasted for three hours. 暴雨已经持续下了3个小时了。

2.经常与现在完成时连用的状语或结构有already, just, so far, in the last [past] few years, it is the first time that..., for five years, since 1980等。如：

I've known her for a long time. 我认识她很长时间了。

I've already posted your letters. 我已把你的信寄出去了。

So far there has been no bad news. 到现在为止还没有坏消息。

Since then, he has developed another bad habit.自那以后，他养成了另一个坏习惯。

合作探究：

1. Maya has been a professional since 1989.

2. So far, it has rained for five hours.

3. Joe has been a student here since March.

4. I haven't been to the cinema for ages.

5. Mary has kept a diary since she was ten years old.

观察以上句子，for和 since的区别为：

for 是介词，（词性）而since可作介词或连接词；for 后面跟表示时间段的结构

since后面跟表示时间点的结构。（点∕段）

预习自测： (十五分钟)

Ⅰ.用动词的适当形式填空.

1．I'm sorry I________(lose)my key. I can't open the door.

2．It is said that the two planets________(move)closer and closer，and that's the reason why so many earthquakes occur.

3．We always ________ (care)for each other and________(help)each other.

4．-What about your company?

-Jobs________(lose)if it closes.

5．This is the first time that I________(see)this kind of film.

Ⅱ.单项填空

1.We ________on our project day and night in the past two weeks.