英语中'to do'的用法不用太复杂,

复制粘贴的不要给他分!
to do在做状语的时候表示目的.to wake up early next morning,he set the alarm.
To do 的被动形式是to be done.完成形式是to have done,进行形式是to be doing.
比如he seems to have finished the task.
He seems to be killed last night.
He seems to be waiting for his girlfriend.
To do还可以做原因状语,i'm glad to meet you.
To do还可表结果,与doing表示的结果不同,doing做结果状语是意料之中的结果,to do 做结果状语是否意料之外的话结果.
比如 he hurried to the airport,only to find that the star had left.
Basketball is being played in more than 80countries,making it the most popular games in the world.

一、做主语
　　1．动词不定式作主语可位于句首。例如：
　　To talk with you is a great pleasure.
　　也可使用it作形式主语，而将其置于句末。例如：
　　It is a great pleasure to talk with you.
　　动词不定式作主语的常用句型有：
　　(1)It is＋adj./n.(＋f...

太简单了。在一个动词后要接另一个动词，只要是没有开始做的动作，都用to do 。

表be to do”的用法
　　　　一般说来，“be to do” 这个结构有两种语法意义，其一是连系动词be+动词不定式做表语，其二是be to是一个独立词汇单位，具有情态含义，可以把它叫做情态习语（modal idiom）。
　　　　一、be +动词不定式，不定式做表语，表示主语和表语在概念上是等同的。如：
　　　　The problem is to find a so...