我知道介词后用动名词，不定式后用原型，我就想问当我后面要接动词的时候，要用动词的正确形式，首先要判断to是什么吧，我怎么判断这个to是介词还是不定式？有什么办法能看出来吗？
有没有to后面既能解动词原形又能接名词的情况？就是说如果这个to在这里做不定式，按理说后面因该接动词原形，可是如果根据语义想接名词，可以吗？？
一般接动词时候都用原型吧
接名词，比如sb. sth.之类的就是作介词用了 这个看得出来的
to doing 的用法很少 我这边给你归纳了一份 附件里也有
请采纳。祝好！
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to doing 用法归纳
一、动词+介词to+动名词<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
1. admit to doing sth 承认做了某事
2. apply to doing sth 适用于做某事
3. object to doing sth 反对做某事
4. see to doing sth 负责做某事
5. stick to doing sth 坚持做某事
6. take to doing sth 喜欢上做某事，逐渐习惯做某事
应用实例：
He admitted having stolen the money. 他承认偷了钱。
These methods apply to learning English. 这些方法适用于英语学习。
He objected to being treated like a child. 他反对被当作小孩子看待。
Reporters should stick to investigating the facts. 记者应坚持调查事实。
Soon he took to sleeping late. 不久他就养成了睡懒觉的习惯。
二、动词+宾语+介词to+动名词
7. apply oneself to doing sth 专心致力于做某事
8. devote sth to doing sth 把……献给做某事
9. devote oneself to doing sth 献身于做某事
10. limit sth to doing sth 把…限制在做某事的范围内
11. reduce sb to doing sth 使某人沦为做某事
12. give one’s life to doing sth 献身于做某事
13. give one’s mind to doing sth 专心做某事
14. have a dislike to doing sth 厌恶做某事
15. have an eye to doing sth 注意做某事
16. have an objection to doing sth 反对(反感)做某事
17. pay attention to doing sth 注意做某事
18. set one’s mind to doing sth 决心做某事
19.make a contribution to doing sth 为某事作出贡献
应用实例：
She applied herself to learning English. 她专心学习英语。
Hunger reduced them to stealing. 饥饿使他们沦落为盗贼。
She devoted herself to helping the poor. 她致力于帮助穷人。
I have a strong dislike to playing cards for money. 我极讨厌打牌赌博。
He has a strong objection to getting up so early.他很反感这么早就起床。
You should pay more attention to uniting and working with those who differ with you. 你应该更注意团结那些自己意见不同的人一道工作。
三、be+形容词（含过去分词）+介词to+动名词
20. be equal to doing sth 等于做某事，能胜任做某事
21. be used to doing sth 习惯于做某事
22. be opposed to doing sth 反对做某事
23. be reduced to doing sth使某人沦为做某事
24. be devoted to doing sth 把时间(钱，精力等)献给做某事
25. be limited to doing sth把……限制在做某事的范围内
应用实例：
This is equal to saying that he’s a cheat. 这就等于说他是个骗子。
She is used to living in the country. 她习惯于住在乡下。
I’m opposed to telling him the news at once. 我反对马上告诉他这消息。
This dictionary is devoted to explaining word usage. 这本词典是解释词的用法的。
四、其他结构+介词to+动名词
26. get down to doing sth开始做某事，认真处理某事
27. look forward to doing sth 盼望做某事
28. What do you say to doing sth? 你认为做某事如何？
应用实例：
We are looking forward to receiving his letter. 我们盼望收到他的回信。
It’s time we got down to some serious work. 我们该认真干点正事了。
What do you say to having a glass of beer? 喝杯啤酒如何?