To please everyone at the same time is impossible To protect environment is important.
不定词当主词时，可以使用假主词代替 It is impossible to please everyone at the same time It is important to protect the environment.
表明不定词意义上的主词时，在前加For It is impossible for me to please everyone at the same time It is important for all of us to protect the environment.
It’s + 形容词（表人格性质）+ of 人 + to V …
1 It's dangerous for children to play on the streets. 2 It's very kind of you to see me off. 3 It was stupid of me to do such a thing.
不定词的否定形： not + to V
Not to depend on others is the best way to success
A doctor’s duty is to take care of sick people
His fault is to talk too much
we decide to put off the meeting.
my son needs to see a dentist
疑问词 + to V ——> 名词片语
How to reduce the costs is a big problem.
The problem is where to set up the tent.
I didn’t know whether to laugh or get angry
Amy was the only person to remember my birthday.
I didn’t have a chance to use English in Japan
（代）名词+ 不定词+ 介词 形式中
I have parents to take care of .
I want a knife to cut it with.
I’m looking for someone to help me
I’m looking for someone who will help me
Do you have anything to write with.
Do you have anything that you can write with
1 he went to Germany to study music. 2 The window was open a few inches to keep the air circulating.
I was shocked to see the scene. We could not but laugh to see it.
有时会伴随only 、never ,有【失望】之意
We were separated never to see each other again.
The police hurried to the house only to find that it was empty.
To hear him talk on the phone ,you would take him for his brother.
I would give you anything to go to the concert.
I would give you anythin if you could go to the concert.
表 [难、易]形容词 + to V
Potery is hard to translate
The rule is easy to remember.
be动词 + 形容词 + 不定词 的惯用表现
be apt to 易于
we are apt to make mistakes.
be ready to 愿意，易于
be willing to 乐意
be eager to 渴望
be likely to 可能
be anxious to 着急
～ enough to V … ——> so ~ that + s + (can) …
1 She was kind enough to offer me her seat 2 I have an enough(a sufficient) income to support you
too ～ to (太～ 而不能… ). ——> so ~ that + s + cannot …
The bed is too small for me to sleep in.
The bed is so small for me so that I can’t sleep in .
I am only to glad to help you
I am very glad to help you
only too + happy/glad /pleased
very happy /glad /pleased
He is not too pround to ask questions of others.
He is too wise not to see the reason.
He is so wise that he can’t but see the reason.
so ~ as to V (非常～以致于 ；到～到程度)
——>so ~ that + S …
1 He was so angry as to be unable to speak
He was so angry that he was unable to speak.
I am not so foolish as to trust him.
I am not such a fool as to trust him.