- 帶 to 的不定詞 = to + 動詞原型
- 不帶 to 的不定詞（又稱「零不定詞」）= 動詞原型
|帶 to 的不定詞||零不定詞|
- 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.
帶 to 的不定詞的作用
帶 to 的不定詞用於很多句構上，通常表達某事的意圖，或者表達某人對某件事的看法。帶有 to 的不定詞可以接的動詞類型有很多，這部分可以參考接不定詞的動詞。
帶 to 的不定詞表明某動作的意圖或目的
在這種情況下，不定詞的 to 意思就跟 in order to 或 so as to 一樣。
- 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.
帶 to 的不定詞用作句中的主詞
- 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.
帶 to 的不定詞表明某件事可以被用來做的事
在這種句型中，帶 to 的不定詞接著是名詞或代名詞。
- 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?
帶 to 的不定詞接在形容詞後
帶 to 的不定詞接在形容詞後的句型很常見，這類語句的公式如下：
主詞 + Be 動詞 + 形容詞 + (for/of 某人) + 帶 to 的不定詞 + (句子的其餘部分)
|主詞||+ Be 動詞||+ 形容詞||(+ for/of 某人)||+ 帶 to 的不定詞||(+ 句子的其餘部分)|
|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.|
評論某事時用帶 to 的不定詞
在對某個名詞評論時使用帶有 to 的不定詞，公式如下：
主詞 + Be 動詞 + 名詞片語 + 帶 to 的不定詞
|主詞||+ Be 動詞||+ 名詞片語||+ 帶 to 的不定詞|
|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.|
副詞和帶 to 的不定詞一起使用
帶 to 的不定詞經常與副詞 too 和 enough 一起用來表達滿意或不滿背後的原因。在句型上，too 和 enough 會被放在其修飾的形容詞、副詞或名詞的前面或後面，就如沒使用帶有 to 不定詞的方式一樣；接著在後面接帶 to 不定詞，表達數量或分量過多、充足或不足的理由。通常帶 to 不定詞以及後面接的所有字詞都可以移除，而剩餘的句子在文法上都還是正確的。
- 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!
帶 to 不定詞和疑問詞一起使用
ask、decide、explain、forget、know、show、tell、understand 等動詞可以接在 where、how、what、who、when 等疑問詞後，加帶 to 不定詞即可。
- 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.
零不定詞（不帶 to 的不定詞）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.
與感知動詞一起使用，句型為動詞 + 受詞 + 零不定詞。
- 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.
零不定詞用在 make 和 let 等動詞後
- 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!
零不定詞用在 had better 的措辭後
- 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.
零不定詞用在疑問詞 why 後
在表達建議時，疑問詞 why 後會接零不定詞。
- 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?