Question

His mother's only wish is ____ him to college.

A. send
B. she wants to send
C. to send
D. sent
为什么不是A

Answer 1

His mother's only wish is ____ him to college.
A. send
B. she wants to send
C. to send
D. sent
为什么不是A

答：
本句话是系表结构，动词不定式to send做表语。选项A.send是动词原形，不是非谓语动词不能做表语。
本句话的意思是：
他母亲唯一的愿望是送他上大学。

某些名词做主语常常用不定式做表语：
除了wishi之外还有：
job,work,desire,task等

再举几例：
His job is to look after sheep on the farm.
他的工作是在农场上放羊。

His task is to look after these old people.
他的任务是照看这些老人。

His desire is to succeed.
（表语） 他的愿望是取得成功。

to加动词原形叫动词不定式，这里的to是不能省略的。

Answer 2

C
见多了就习惯了，is to do

Answer 3

因为后面要做目的状语 所以要加to

Answer 4

be后不能直接接动词 be+v.ing