您正在看的英语语法是:英语语法难点精析（二）。 fell into the lake，Eric sprang to his feet，and went on the rescue.
2)另一类是某些使役动词，如make, let，have等。如：
    Let him do it.让他做吧。
    I would have you know that I am ill．我想要你知道我病了。
  (注)：
    ①上述感觉动词与使役动词转换为被动结构时．其后的不定式一般需带to，如：
    He was seen to come．
    The boy was made to go to bed early.  
    ②在动词find与help之后，不定式可带to亦可不带to，如:
    He was surprised to find the sheep (to) break fence at this season．他发现羊在此季节越出栅栏，感到惊讶。
  3)在do nothing／anything／everything but(except)结构中。例如：
    Last night I did nothing but watch TV．昨天晚上，我除了看电视别的什么也没有干。
      但是，如果谓语动词不是“do nothing，anything，everything”，那么but(except)所跟的不定式则仍须带。
    The doctor told him nothing but to stop smoking．医生除了让他戒烟，其它什么都没有说。
There was nothing for them to do but to remain silent．除了保持沉默以外，他们没有别有别的办法。
（4）不定式与动名词的逻辑主语和分词独立结构
1)不定式的逻辑主语为：for +名词(或代词宾格)+ 不定式。例如：
    I found it impossible for him to do the job alone．我发现他—个人干这活是不可能的。
    (注)在表示人物性格、特性等的形容词后面，常用of引出不定式的逻辑主语。例如：
    It was wise of him to do that．他那样做是明智的。
2)动名词的逻辑主语为；①人称代词的所有格+动名词；②名词’s+动名词。例如：
    Tom insisted on my going with them．他坚持要我和他们一起去。
    He dislikes his wife’s working late．他不喜欢他妻子工作得很晚。
3)某些形容词，如：careless等不定式后可以加of来引导出其逻辑主语。这类词主要有：absurd, bold, brave, courageous, careful, careless, clever, wise, foolish, silly, stupid, good, nice, kind thoughtful, considerate, greedy, generous, honest, modest, polite, rude, cruel ,selfish, wicked, wrong等
    It is very kind of you to help me．你帮助我太好了。
    间或也可用for + there to be表示（而且there后面的不定式只能是to be）。
It’s a great pity for there to be much trouble in the company.太遗憾了公司里有这么多的麻烦。
7．非谓语动词中的有关句型
（1）动名词作主语的句型
  1）Doing...+ v. Reading is an art.阅读是门艺术。Seeing is believing.眼见为实。
  2) It is + no use, no good (fun, a great pleasure, a waste of time, a bore...)等名词+doing sth.
It is no use crying.哭没有用。It is no good objecting.反对也没有用。
It is a great fun playing football．打篮球很有趣。
It is a waste of time trying to eXPlain．设法解释是浪费时间。
  3)It is + useless (nice, good，interesting, eXPensive等形容词)+ doing sth．
    It is useless speaking.光说没用。
    It is nice seeing you again．真高兴又遇到了你。
    It is good Playing chess after supper．晚饭后弈棋挺好。
    It is eXPensive running this car．开这种小车是浪费。
  4)There is no + doing.．.(there is no 表“不可能”)
    There is no telling what he is going to do．说出他要干什么是不可能的。
    There is no saying what may happen.说出将要发生什么是不可能的。
  5)There is no use (good/point/sense/harm)+doing sth.做某事没用(不好/意义/重要性)
    There is no use crying over spilt milk．牛奶洒了，哭也无用。
  6)have difficulty /trouble/problem + (in)+doing