詞不定式的一般形式是“to＋動(dòng)詞原形”,但在下面情況中to要省略：
一、在感官動(dòng)詞see,hear,watch,notice,feel,look at,listen to等及使役動(dòng)詞make,let,have等后作賓語補(bǔ)足語的動(dòng)詞不定式要省略to.如：
We saw him get on a bus.
The boss often made the workers work for over 12 hours a day.
注意：以上情況如果用于被動(dòng)語態(tài)時(shí),不定式符號(hào)to一定要補(bǔ)回.如：
He was seen to get on a bus.
The workers were often made to work over 12 hours a day.
二、在動(dòng)詞help后作賓語補(bǔ)足語的動(dòng)詞不定式符號(hào)to可帶可不帶.如：
I often help my mother (to) do housework.
三、在had better,would rather后動(dòng)詞不定式不能帶to.如：
You’d better not go out at night.
The boy would rather stay at home by himself.
四、當(dāng)兩個(gè)或兩個(gè)以上的動(dòng)詞不定式并列使用時(shí),通常只有第一個(gè)不定式前帶to,第二個(gè)及以后的不定式可省略to.如：
I want to have a read and write.
He wants to have a rest and have a cup of tea.
五、“Will(Would) you please＋不帶to的不定式”.如：
Would you please not do that again?
六、當(dāng)不定式作介詞but,except的賓語,表示“除了……不/沒有做……”時(shí),不定式要省略to.如：
She does nothing but watch TV.
She doesn’t want to do anything except sleep