to什么时候是介词.什么时候是不定式...要怎么判断 我明天考试.快回答！！！！我还会多给分

Question

在原金上多给20分

Answer 1

to后面是名词或名词性从句时是介词，。后面是动词如to do,to have done，to be done等时是动词不定式，
做介词的情况不多,下列记着就行了:
look forword to
be used to（表习惯于做某事时）
get down to
object to
be devoted to
这些不常见：
make a contrybution to
resort to
react to
contribute to
be accustomed to
be committed to
be exposed to
be dedicated to
be opposed to
be contrary to
with regard to
with a view to
as to
in contrast to追问

“名词或名词性从句”是什么

Answer 2

to后面是名词或名词性从句时是介词，。后面是动词如to do,to have done，to be done等时是动词不定式，
做介词的情况不多,下列记着就行了:
look forword to
be used to（表习惯于做某事时）
get down to
object to
be devoted to
这些不常见：
make a contrybution to
resort to
react to
contribute to
be accustomed to
be committed to
be exposed to
be dedicated to
be opposed to
be contrary to
with regard to
with a view to
as to
in contrast to

Answer 3

这要看to后面跟的是什么词,to后面是名词或名词性从句时是介词，。后面是动词,如to do,to have done，to be done等时是动词不定式.

Answer 4

to当介词使用时，后面加名词或doing等，当不定式时后面加do动词原形
(哪些动词不定式必须省略to? 一般带有不定式的动词，to不能省略。
能够省略的情况有：1.情态动词后。2.少数动词，表示使、让意思的动词，在被动语态中，可以省去to。3.部分结构，如：do nothing but ... 后跟动词原形。)