动词不定式的不同形式(以do为例)解析

• 动词+ 疑问词+to 不定式 ( decide; learn ; remember; forget ,know， understand, wonder …) • I don’t know what to say. • Many teachers have learned how to drive.
• 作动词宾语的不定式： 动词+ to不定式. (want; plan; wish; hope; decide …), 可接不定式作宾语的动词有： afford负担得起/ agree 同意/ aim以…… 为目标/ ask 要求/ attempt 尝试 /care喜爱/ choose决定/ continue 继续 /decide决定/ desire要求/ determine决 心/// expect 期待/ fail不能/ hope 希望 intend 打算/long渴望 / manage设法 offer表示愿意/ plan 计划/ prefer 宁愿/ pretend 假装/ promise 答应/refuse 拒 绝 want 想要/ wish希望
动词不定式的不同形式（以do为例）
主动 一般式 to do 被动 to be done
进行式
完成式 完成进行式
Hale Waihona Puke Baidu
to be doing
to have done to have been doing to have been done
• 作主语的不定式: To do …is …
• It’s +adj. + to do (It’s + adj for sb to do Cf It’s + adj + of sb to do) • It’s + n + to do ( It’s fun/ a pity/ a shame/ good manners/ bad manners to do ) • It’s + prep + to do (It’s of use/ of value/ beyond me/ not within my power/ just like her +to do) • It + V + n + to do ( take/ cost/ require)
• It is +形容词+for sb +不定式”结构中，形 容词通常表示事物的性质，如important, possible, impossible, necessary, difficult, hard, reasonable等。 • It is easy for me to see through his trick.我很容易看穿他的鬼把戏。(=For me to see through his trick is easy.) • It is hard for him to get rid of his bad habits. 他很难改掉自己的坏习惯 • It is good for you to give up smoking. 戒烟对你有好处。（强调的是give up smoking 这一行为
• It is + 形容词 + for/of sb + to do 结构 • 在“It is +形容词+ of sb +不定式”结构 中，形容词往往表示人物的性格和特征，如 kind, silly, good, unwise, clever, etc • It's kind of you to think so much of us. • How careless it is of him to break such a valuable vase! • It is good of you to help me with my English.
• It seemed a pity to have wasted so much time It takes twenty minutes to walk here. • It takes 5 months to finish the task. It takes a strong man to move the table. • It costs 5000 yuan to fly to Australia. • It requires patience to do the experiment.
.动词+ 形式宾语 + 补足语+ 不定式 V+ it + adj./n. + to do （feel, find, make, think, consider ） 1. I think it better to start off early. 2. People find it very necessary to have sports often. 3. We consider it important to learn English well. I feel it my duty to help you with your studies. She made it a rule to get up at five
• 注意： • 当主语和表语都是不定式时，不能用形式 主语代替动词不定式。 • To respect others is to be respected. 尊重别人就是尊重自己。 • To become a slave is to give up one's freedom. 做奴隶就等于放弃自由。
• 作主语的不定式:
1.To tell a lie is wrong. (It is wrong to tell a lie.)
2.To be invited here is an honour. (It is an honour to be invited here.) 3. It is impossible for him to master the art of speaking. 5.It was brave of her to save the pupils. (=She was brave to save the pupils.)