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“too...to...结构”中不定式用主动还是被动?

2017-02-24来源:和谐英语

too...to...结构”中不定式用主动还是被动? 

【问】这是2010年山东卷高考题:

That’s the new machine ______ parts are too small to be seen.

A. that B. which C. whose D. what

这个句子中,不定式用了被动形式,请问:能用主动形式吗?

【答】That’s the new machine whose parts are too small to be seen.这句话,不定式完全可以用主动形式:

That’s the new machine whose parts are too small to see.

在“主语+ be + too+形容词+不定式”句式中,动词不定式一般表示结果。当something充当了句子的主语,跟不定式存在逻辑上的被动关系时,不定式既可以用主动形式,也可以用被动形式。这两者的区别是:

主动形式忽略了句子主语跟不定式的被动关系,而强调了人的主体行为,即人去做这件事,因此,可以在不定式之前加上逻辑主语for somebody。

被动形式强调了句子主语跟不定式的被动关系,在不定式之前不能加上逻辑主语for somebody,但可以在被动的不定式之后加上by somebody,以表示这个动作的执行者。例如:

第一组:

1. That’s the new machine whose parts are too small for the engineers to see.

2. That’s the new machine whose parts are too small to be seen by the engineers.

第二组:

1. Bacteria are too small for the naked eye to see.

2. Bacteria are too small to be seen by the naked eye.

第三组:

1. The big stone is too heavy for a child to lift.

2. The big stone is too heavy to be lifted by a child.

在“主语+ be +形容词+enough+不定式”句式中,动词不定式也表示结果,同样有类似用法。例如:

第一组:

1. The problem is easy enough for the teacher to work out.

2. The problem is easy enough to be worked out by the teacher.

第二组:

1. It looks as if the water isn’t clean enough for the animals to drink.                                        

2. It looks as if the water isn’t clean enough to be drunk by the animals.      

第三组:

1. Are the apples ripe enough for the kids to eat?            

2. Are the apples ripe enough to be eaten by the kids?(www.hxen.net)

以上句子,在主动的不定式之前,并非一定要加for sb.,在被动的不定式之后,并非一定要加by sb. 这是理解问题的一种思路,帮助分清主动和被动之间的差异。