非谓语是指动词在句子中不作谓语，而作其他成分的形式，包括不定式、动名词和分词。其中，不定式的形式包括to do，动名词的形式是doing，分词则分为现在分词doing和过去分词done。
在英语句子的简单句中，我们可以遵循“主语+谓语+非谓语”去分析，一个简单句只有一个谓语，后面再出现动词就是非谓语。谓语考察“时态和语态”，非谓语考察“动词形式”，不定式to do(包括省略to的不定式)、动名词doing、现在分词doing和过去分词done，因为动名词和现在分词形式一样，因此可归纳为，只考察“to do/do/doing/done” 4个结构。
非谓语详解
不定式to do的用法：表目的、表将来。表示将要发生或计划要发生的动作，也可以作为目的状语、结果状语和表语等。例如：
I want to study abroad next year.（我明年想要出国留学。）
She went to the supermarket to buy some groceries.（她去了超市买了些食品杂货。）
His dream is to become a successful businessman.（他的梦想是成为一个成功的商人。）
动名词doing的用法：具有名词的性质，因此在句中可以充当主语、表语、宾语、定语，但是不能充当状语。例如：
I enjoy swimming in the sea.（我喜欢在海里游泳。）
Reading books is good for your mental health.（读书对心理健康有好处。）
She apologized for arriving late.（她为迟到道歉。）
现在分词doing：表主动、表进行。现在分词表示正在进行的动作或状态，它通常被用作一个形容词，可以在句子中作定语、表语等。现在分词表示的是一个正在进行的动作或状态，相当于中文中的“正在进行的”。它们可以作为形容词、状语、介词短语的补语等。例如：
The girl crying in the corner is my sister.（在角落哭泣的那个女孩是我妹妹。）
过去分词done：表被动、已完成。表示完成的动作或状态，它们也可以作为形容词、状语、介词短语的补语等。例如：
The book written by Hemingway is a classic.（海明威写的书是经典之作。）
中学常考-非谓语mind map梳理
to do/ doing 易错短语辨析
习题-Exercise
Fill in the blanks with the appropriate form of the verb in parentheses.
I prefer _____________ (do) my own laundry instead of taking it to the laundromat.
答案：doing
She promised _____________ (finish) her homework before going out with friends.
答案：to finish
The children enjoy _____________ (play) in the park after school.
答案：playing
He was asked _____________ (give) a speech at the conference next month.
答案：to give
Have you ever tried _____________ (ski) before?
答案：skiing
She regrets _____________ (not study) harder for the exam.
答案：not studying
After _____________ (work) all day, I just want to relax and watch TV.
答案：working
He admitted _____________ (cheat) on the test and was given a failing grade.
答案：cheating
She needs _____________ (buy) some groceries on her way home from work.
答案：to buy
The students are excited about _____________ (finish) the school year and starting summer vacation.
答案：finishing