- 带 to 的不定词 = to + 动词原型
- 不带 to 的不定词（又称「零不定词」）= 动词原型
|带 to 的不定词||零不定词|
- I decided not to go to London.
- He asked me not to be late.
- I'd like you not to sing so loudly.
- I'd rather not eat meat.
- I might not come.
带 to 的不定词的作用
带 to 的不定词用于很多句构上，通常表达某事的意图，或者表达某人对某件事的看法。带有 to 的不定词可以接的动词类型有很多，这部分可以参考接不定词的动词。
带 to 的不定词表明某动作的意图或目的
在这种情况下，不定词的 to 意思就跟 in order to 或 so as to 一样。
- She came to collect her pay cheque.
- The three bears went to find firewood.
- I am calling to ask you about dad.
- You sister has gone to finish her homework.
带 to 的不定词用作句中的主词
- To be or not to be, that is the question.
- To know her is to love her.
- To visit the Grand Canyon is my life-long dream.
- To understand statistics, that is our aim.
带 to 的不定词表明某件事可以被用来做的事
在这种句型中，带 to 的不定词接着是名词或代名词。
- The children need a garden to play in.
- I would like a sandwich to eat.
- I don't have anything to wear.
- Would you like something to drink?
带 to 的不定词接在形容词后
带 to 的不定词接在形容词后的句型很常见，这类语句的公式如下：
主词 + Be 动词 + 形容词 + (for/of 某人) + 带 to 的不定词 + (句子的其馀部分)
|主词||+ Be 动词||+ 形容词||(+ for/of 某人)||+ 带 to 的不定词||(+ 句子的其馀部分)|
|It||is||good||of you||to talk||to me.|
|It||is||important||to be patient.|
|It||is||important||for Jake||to be patient||with his little brother.|
|The dog||is||naughty||to destroy||our couch.|
评论某事时用带 to 的不定词
在对某个名词评论时使用带有 to 的不定词，公式如下：
主词 + Be 动词 + 名词片语 + 带 to 的不定词
|主词||+ Be 动词||+ 名词片语||+ 带 to 的不定词|
|It||was||a stupid place||to park.|
|That||is||a dangerous way||to behave.|
|What you said||was||a rude thing||to say.|
|This||is||the right thing||to do.|
|Those||were||the wrong kind of eggs||to buy.|
|Jim||is||the best person||to hire.|
副词和带 to 的不定词一起使用
带 to 的不定词经常与副词 too 和 enough 一起用来表达满意或不满背后的原因。在句型上，too 和 enough 会被放在其修饰的形容词丶副词或名词的前面或后面，就如没使用带有 to 不定词的方式一样；接着在后面接带 to 不定词，表达数量或分量过多丶充足或不足的理由。通常带 to 不定词以及后面接的所有字词都可以移除，而剩馀的句子在文法上都还是正确的。
- There's too much sugar to put in this bowl.
- I had too many books to carry.
- This soup is too hot to eat.
- She was too tired to work.
- He arrived too late to see the actors.
- I've had enough food to eat.
- She's old enough to make up her own mind.
- There isn't enough snow to ski on.
- You're not old enough to have grand-children!
带 to 不定词和疑问词一起使用
ask丶decide丶explain丶forget丶know丶show丶tell丶understand 等动词可以接在 where丶how丶what丶who丶when 等疑问词后，加带 to 不定词即可。
- She asked me how to use the washing machine.
- Do you understand what to do?
- Tell me when to press the button.
- I've forgotten where to put this little screw.
- I'm not sure I know who to call.
零不定词（不带 to 的不定词）的作用
- She can't speak to you.
- He should give her some money.
- Shall I talk to him?
- Would you like a cup of coffee?
- I might stay another night in the hotel.
- They must leave before 10.00 a.m.
与感知动词一起使用，句型为动词 + 受词 + 零不定词。
- He saw her fall from the cliff.
- We heard them close the door.
- They saw us walk toward the lake.
- She felt the spider crawl up her leg.
零不定词用在 make 和 let 等动词后
- Her parents let her stay out late.
- Let's go to the cinema tonight.
- You made me come with you.
- Don't make me study that boring grammar book!
零不定词用在 had better 的措辞后
- We had better take some warm clothing.
- She had better ask him not to come.
- We had better reserve a room in the hotel.
- You'd better give me your address.
- They had better work harder on their homework.
零不定词用在疑问词 why 后
在表达建议时，疑问词 why 后会接零不定词。
- Why wait until tomorrow?
- Why not ask him now?
- Why leave before the end of the game?
- Why walk when we can go in the car?
- Why not buy a new bed?