内容正文:
专题十四 非谓语动词
知识导图
考法精讲
命题点 1 动词不定式
1. 基本形式:
肯定形式:to+动词原形(不定式符号to有时可以省略);否定形式:not to+动词原形。不定式没有人称和数的变化。如:He asked me to play chess with him. 他让我和他下象棋。
2. 功能
动词不定式具有名词、形容词和副词的特征,因此可以在句中作主语、宾语、宾语补足语、表语、定语和状语。
(1)作主语
不定式作主语,相当于名词或代词的作用,往往用形式主语it代替,而真正的不定式主语则被后置。因此,常用句型:It's +adj. (+for/of sb.)+to do sth. 如:To learn words by remembering them in groups is helpful.=It is helpful to learn words by remembering them in groups. 通过小组记忆单词有助于学习单词。
it代替不定式作形式主语的句型:
①It+be+形容词+不定式。如:It's hard to say which one is better. 很难说哪一个更好。
②It+be+名词+不定式。如:It was great fun to have a picnic there. 在那里野餐很有趣。
③It takes /took sb. some time+不定式。 如:It took me nearly two hours to get to the nature park. 我花了将近两个小时才到达自然公园。
(2)作宾语
①动词的宾语(动词+to do),如:I decided to change my eating habits. 我决定改变我的饮食习惯。
②和疑问词who,what,when,where,how,which等连用,一起作tell,ask,know,show等动词的宾语。如:She showed us how to do the experiment. 她向我们展示了如何做这个实验。
I don't know what to do. 我不知道做什么。
③用it作形式宾语时,将真正的宾语后置(2018.42),如:
I think it easy to finish the work within one day. 我认为在一天内完成这项工作很容易。
【拓展】
常见接动词不定式作宾语的动词(动词+to do sth.)
afford负担得起
agree同意
choose选择
hope希望
want想要
plan计划
decide决定
expect期望
fail未做到
offer主动提出
happen发生
prepare准备
learn学习
like喜欢
manage设法做成
refuse拒绝
promise承诺
try努力
(3)作宾语补足语(语法选择:2022.34, 2020.33)
在“动词+宾语+不定式”结构中,不定式作宾语补足语。如:The teacher asked us not to run in the hallway. 老师要求我们不要在走廊里跑。
【拓展】常见接动词不定式作宾语补足语的词(组)(动词+sb. to do sth.)
advise建议
allow 允许
ask要求
expect期望(2020.33)
force强迫
encourage 鼓励
invite 邀请
order命令
teach 教
tell告诉(2022.34)
want想要
warn警告
wish希望
would like愿意
remind 提醒
(4)作状语(语法选择:2021.38;往年单项填空:2019.36)
①作目的状语(2021.38, 2019.36)。常用结构:in order to do, so as to do, ...only to do(仅仅为了)。如:The teacher raised his voice to make him heard clearly. 老师提高嗓门使他被听得清楚。
②作结果状语。常用结构:so...as to, too... to..., enough... to..., only to do(表示没有预料到或事与愿违的结果)。如:The box is too heavy to carry. 这个箱子太重了以至于搬不动。
③作原因状语。如:Ben was so excited to know that he had won the first place in the exam. Ben得知他在考试中获得了第一名后非常兴奋。
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