非限定动词 D

张文

动词不定式的否定结构
动词不定式的否定结构由在不定式符号to之前加上not而成。如： He decided not to go home.他决定不回家。
The teacher warned the pupils not to go skating on thin ice.教师警告学生不要在薄冰上滑冰。
I told him not to open the door.我叫他不要开门。 疑问词 + 动词不定式
疑问代词who，what，which和疑问副词when，where，how等后加动词不定式，构成一种特殊的动词不定式短语，可在句子中作主语、宾语、表语等成分。如：
When to start has not been decided.何时动身尚未决定。(作主语) They told her where to find her little brother.他们告诉她到哪里找她的小弟弟。(作宾语)
The teacher showed the students how to do the exercise.老师教学生
如何做练习。(作宾语)
He thought a lot about how to improve his English pronunciation.他对如何提高英语语音想得很多。(作介词的宾语)
动词不定式复合结构"for + 名词(或代词宾格) + 动词不定式" 在这种结构中的for本身无意义。名词(或代词宾格)形式上是for的宾语，但在逻辑上可以说是动词不定式的主语。这种不定式复合结构在句子里可作下列成分：
1)主语
For us to learn foreign languages is important.学习外语对我们来说是重要的。
在句中，for us在逻辑上是to learn foreign languages的主语。这种结构作主语时，和简单的动词不定式结构一样，一般都用引词讧来代表并放在句首，"for + 名词 (或代词宾格) + 不定式"则放在句末。如：
It is important for us to learn foreign languages.
It is necessary for us to learn from each other.我们必须相互学习。 2)表语
It is for you to decide.这得由你决定。 3)宾语
Can you arrange for a car to take us there?你能安排一辆汽车送我们到那里去吗?
4)定语
There is a lo to work for us to do.有很多工作要我们去做。 5)状语
The policeman blew his whistle for the carts to stop.警察吹哨要那几辆大车停下来。(作目的状语)