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2021年1月30日发(作者：晨光中的咏叹调)
半助动词

百科名片

半助动词在功能上介乎主动词和助动词之间的一类结构，称为半助动词。常见的半助动词有
be about to, be due to, be going to, be
likely to, be meant to, be obliged to, be supposed to, be willing to, have to, seem to, be unable to, be unwilling to
等。它们可与主动词搭配构成复杂动词词组并表示情态意义，有时也可与助动词搭配。

目录

实例

半助动词的其他用法

转换关系

省略式

注意

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实例





























The boy has to make a living by begging.
男孩不得不通过乞讨维持生计。

He is unwilling to help me with my English.
他不愿帮我学习英语。

Every clause is obliged to obtain a finite verb.
每个句子必须包括一个限定动词。

We were about to start when it rained.
下雨时，我们即将出发。

He seems to be very disappointed.
他好像非常失望。

I don’t have to buy a new house.

我不必买新房子。

He didn’t seem to feel in love with her.

他好像没有爱上她。

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半助动词的其他用法



带有半助动词作为动词词组的组成部分的句子，有的可以转换为
“ It„that
-
分句”结构，而有的却不可以。从这个角度看，半助动词可分
为两类：
一类 是可以作上述转换的，
其中包括
be
cer-tain
to
，
be
（
un
）
likely
to
，
appear to
，
happen to
，
seem to
等。例如：



They are certain to win the game
．他们肯定会在比赛中获胜。



→It is certain that they will win the game．



He is likely to let you down
．他可能使你失望。



→It is likely that he will let you down．



He appears to have many friends
．看来他有许多朋友。



→It appears that he has many friends．



He seems to be enjoying himself
．看来他玩得很快活。



→It seems that he is enjoying himself．



I happen to have had some nasty experiences in dealing with him
．



我恰巧有过一些和他打交道的不愉快的经历。



→It happens that I have had some nasty experiences in deal－
ing
with him
．



Some members of the committee seem to have been bribed
．



委员会的一些成员看来是受了贿赂。



→It see
ms that some members of the committee have been bribed
．



另一类半助动词不可以作上述转换，这一类包括
be
about
to
，
be
bound
to
，
be
going
to
，
be
to
，
had
better
，
have
to
，
have
got
to
，
tend
to
等。
例如：



He is adout to arrive
．他即将到达。



He is bound to win
．他一定会获胜。



The boy tended to be late
．这孩子老是迟到。



不可以转换为：



*It is about that he will arrive
．



*It bound that he will win
．



*It tended that the boy was late
．



半助动词也可用于
there
－存在句。例如：



There's going to be a storm
．就要有暴风雨了。



There's to be an investigation
．要作一次调查。



There has to be a mistake
．一定有错。



There's sure to be some rain tonight
．今晚一定有雨。



There's likely to be a large audience
．观众人数可能很多。



There's certain to be trouble at the factory
．厂里一定有麻烦。



There seems to be a widespread change of attitude


看来态度有普遍的改变。



There appears to be no doubt about it
．



看来这是毫无疑问的了。

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转换关系



凡是能够作上述句型转换的半助动词，在
there-
存在句中 ，也可作类似
的转换。现在，我们再从相反的方向来看这种转换关系：



It is likely that there'll be a large audience
．



→There is likely to be a large audience．



It is certain that there is trouble at the factory
．



→There is certain to be trouble at the factory．



It seems that there's a widespread change of attitude
．



→There seeme to be a widespread change of atti
tude
．



It appears that there's no doubt about it
．



→There appers to be no doubt about it．



顺便说一句，如果“ It„that＋
there-
存在句”的主句谓语动词是
is
said
，
is believed
等被动态，那末转换过来的
th ere-
存在句的谓语动词也
应是被动态。例如：



It is said that there's trouble at the factory
．据说厂里有麻烦。



→There
's said to be trouble at the factory
．

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