非谓语动词（一）：不定式与动名词

本节导读

一个句子里只能有一个谓语动词，如果还想用别的动词，就要把它变成非谓语形式。非谓语动词有三种：不定式（to do）、动名词（doing）和分词（doing / done）。这一节讲前两种，下一节讲分词。

考试里最常见的考法是：某个动词后面接 to do 还是接 doing，某个短语里的 to 是不定式符号还是介词，以及 remember to do 与 remember doing 这类意思不同的搭配。

不定式：to do

不定式在句子里可以充当多种成分：

作用	例句
主语	To learn English well is not easy.
宾语	I want to buy a new phone.
宾语补足语	The teacher asked us to read the text.
表语	My dream is to be a doctor.
目的状语	He got up early to catch the early bus.
定语	I have a lot of homework to do.

常接不定式的动词

后面直接接 to do 的动词：want、hope、wish、decide、plan、refuse、learn、manage、agree、promise、expect、offer、fail、choose。

后面接「宾语 + to do」的动词：ask、tell、want、allow、advise、invite、teach、order、encourage、force、persuade、would like。

I decided to learn English.
我决定学英语。

My teacher advised me to read more.
老师建议我多读书。

省略 to 的不定式

下面这些情况，不定式要省略 to：

• 情态动词后面：can、must、may、should 等。
• let、make、have + 宾语 + do：The teacher made us repeat the sentence.
• see、hear、watch、notice、feel + 宾语 + do：I heard him sing.
• 固定结构：had better do、would rather do、why not do。

make、see 等词变成被动句后，to 要补出来，上一节已经讲过：They were made to work late.

几个常见的不定式结构

• too + 形容词 + to do：太……而不能……。He is too young to go to school.
• 形容词 + enough to do：足够……可以……。He is old enough to go to school.
• in order to / so as to do：为了……。He ran fast in order to catch the bus.

动名词：doing

动名词是动词加 -ing，具有名词的作用，可以充当主语、宾语、表语，也可以作介词的宾语：

作用	例句
主语	Swimming is good for your health.
宾语	I enjoy reading.
介词宾语	He is good at drawing.
表语	My hobby is collecting stamps.

常接动名词的动词

enjoy、finish、mind、avoid、practise、suggest、keep、miss、consider、imagine、risk、admit、deny、delay、give up、put off、can't help、insist on。

Would you mind opening the window?
你介意打开窗户吗？

介词 to 后面用动名词

有些短语里的 to 是介词，不是不定式符号，后面要接动名词或名词：