不定式用法及例句

例：Her mom must have been seriously ill then. ·在should/ought to之后表示未能实现的事 例：You ought to have kept your words. 5. 代不定词：

（1）目的：为了避免相同动词的重复，在句子意思非常明确的情况下用to代替toV，to称为代不定词 例：You don’t have to eat it if you don’t want to (eat it). 6. 分离不定词：

（1）将修饰toV的副词，放在to和V之间：to ad. V （2）not/never放在to之前：not/never to V （3）副词为否定放toV之前 例：I wish to utterly forget my past.

She made up her mind never to return. 7. 独立不定词

（1）用来修饰整个句子 例：to speak strictly 严格来说

to be frank (with you) 坦白说 to begin with 一开始 to tell the truth 老实说 to be honest 诚实说

to make matters worse 更糟糕的是 to be sure 的确

to be brief 简单扼要的说 to say nothing of not to speak of 更不用说 not to mention

to do…justice 对…公平的评判 to say the least of it 保守的说 strange to say 奇怪的是 so to speak 可以说是

not to say+adj. 即使不能说是…

八、toV的惯用表现

1. had better +原型toV：最好… 例：We had better leave it unsaid.

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·leave 让…保持在…样的状态 离开 +for 前往

2. would/rather + 原型不定词…+ than + 原型不定词 宁愿…而不愿 . would/had sooner +原型不定词…+ than +原型不定词 例：I would rather go with you than stay here alone. 3. do nothing but + 原型不定词 什么都不做，只… 例：He did nothing but eat all day. 4. choose

want + nothing but + toV 除了…其他都不想 expect desire

例：She desires nothing but to live peacefully. 5. can’t but + 原型不定词

can’t help + 动名词 不得不…；忍不住… can’t help but + 原型不定词

例： I couldn’t but cry.

When I heard the news, I couldn’t help crying. I couldn’t help but cry. 6. have only toV 只要…就行 例：You have only to follow his counsel. 7. used toV 以前习惯…；过去经常… 例：My father used to smoke, but now he doesn’t. 8. be used to Ving 习惯…

例：I am used to staying/sitting up late night.

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