1. 在英语中，大多数谓语动词后再接动词，要用不定式。不定式的否定，是在不定式前加否定词not（或never）。例如：① want to do sth. 想做某事② want sb. to do sth. 想要某人做某事③ would like / would love to do sth. 想要做……④ tell sb. (not) to do sth. 告诉某人做 <别做> 某事⑤ ask sb. (not) to do sth. 要求某人做 <别做> 某事⑥ be sorry to do sth. 对做某事感到抱歉⑦ be happy to do sth. 对做某事高兴⑧ teach sb. to do sth. 教某人做某事⑨ agree to do sth. 同意做某事⑩ decide to do sth. 决定做某事⑾ hope to do sth. 希望做某事⑿ promise to do sth. 许诺、答应做某事⒀ make up one’s mind(s) to do sth. 下决心做某事⒁ advise sb. to do sth. 建议某人做某事⒂ be afraid to do sth. 害怕、不敢做某事⒃ be able to do sth. 能够做某事⒄ be about to do sth. 马上要做某事⒅ allow sb. to do sth. 允许某人做某事⒆ warn sb. (not) to do sth. 警告某人做 <别做> 某事⒇ encourage sb. to do sth. 鼓励某人做某事2. 有些谓语动词后，再接动词，既可以接不定式，也可以接动名词。词义无很大区别。例如：begin to do / doing sth.start to do / doing sth.continue to do / doing sth.3. 有些谓语动词后，再接动词，既可以接不定式，也可以接动名词，但词义有区别。例如：① like doing sth. 喜欢做某事 (一种长期的习惯)like to do sth. 喜欢、要做某事 (一次偶然、暂时的行为)② remember to do sth. 记得去做某事 (还没有做，要去做)remember doing sth. 记得做过某事 (事情以前做过了)③ forget to do sth. 忘记去做某事 (还没做，要去做)forget doing sth. 忘记曾做过某事 (事情以前做过了)④ stop to do sth. 停下来去做另一件事stop doing sth. 停止做正在做的事⑤ try to do sth. 努力、尽量去做某事try doing sth. 尝试、试着做某事⑥ mean to do sth. 打算做某事mean doing sth. 意味着做某事⑦ regret to do sth. 遗憾去做某事regret doing sth. 后悔曾做过某事⑧ go on to do sth. 完成一件事，接着做另一件事go on doing sth. 没完成某件事，继续做同一件事⑨ can’t help to do sth. 不能帮助做某事can’t help doing sth. 情不自禁地做某事、忍不住做某事4. 有些谓语动词或动词短语后，再接动词，只能接动名词，不能接不定式。例如：enjoy doing sth. 喜欢做某事finish doing sth. 完成、做完某事practice doing sth. 练习做某事mind doing sth. 介意做某事suggest/ advise doing sth. 建议做某事avoid doing sth. 避免做某事imagine doing sth. 想象做某事be busy (in) doing sth. 忙于做某事sb. spend some time/ money (in) doing sth. 某人花费时间/金钱做某事keep (on) doing sth. 继续做某事get/ be used to doing sth. 习惯于做某事put off doing sth. 推迟做某事give up doing sth. 放弃做某事5. 使役动词（即： 表示“使、让”词义的动词）后只能接不带to的不定式（也就是：动词原形）。例如：let sb. do sth. 让某人做某事make sb. do sth. 让某人做某事have sb. do sth. 让某人做某事have sth. done 让某事被做、让别人替自己做某事6. 动词help后既可以接不带to的不定式，也可以接带to的不定式，但词义有一定的区别。help sb. (to) do sth. 帮助某人做某事7. 介词后接动词时，只能用动名词形式。例如：be good at doing sth. 擅长做某事do well in doing sth 擅长做某事be interested in doing sth. 对做某事感兴趣be afraid of doing sth. 害怕做某事thank sb. for doing sth. 因某事感谢某人look forward to doing sth. 期待、盼望做某事feel like doing sth. 想要做某事be worth doing 值得做8. 英语中，动词或动词短语是不能直接做主语的。如果需要用其做主语时，方法有二：①将it放在句首，做形式主语，将动词或动词短语改为不定式或不定式短语放在句尾做真正的主语。常常构成如下句型：It’s ＋adj. for sb. to do sth.（有时，也可直接将不定式或不定式短语放在句首做主语。 句型为：To do sth. is ＋adj. for sb.）②将动词或动词短语改为动名词或动名词短语放在句首做主语。常常构成如下句型：Doing sth. is ＋adj. for sb.动词不定式与动名词的区别：to+V 放句首为动词不定式，用法与V+ing差不多，多用于后面所说的事情还没有发生。例：To be a author is my dream.V+ing 放句首是动名词，其相当于名词，例：Doing lots of exercise is good for health.一般来讲，to+ v. 表主动，表将来，表一次行动作。 -ing 表主动，表进行。动词不定式与动名词的一些用法：不定式与动名词都可以在句中作主语、宾语、表语和定语,但用法不尽相同。1．作主语一般情况下,不定式与动名词作主语可以互换,也常常可以用it充当形式主语,而把不定式和动名词放在句子的后半部分。但二者也有区别,不定式常常指某次具体的、将要发生的行为;而动名词则表示一般的、抽象的行为。例如:To save money now is not easy. 现在攒钱不容易。Saving money is a good habit. 攒钱是个好习惯。2．作定语不定式多为后置定语,动名词多为前置定语;不定式多表示将来的动作,动名词只能表示事物的属性、用途等。例如:He is looking for a room to live in.他正在找一间房子去住。Take these sleeping pills and you'll sleep better. 吃了这种安眠药,你会睡得更好。3．作宾语：有些动词后只能跟不定式作宾语,不能跟动名词作宾语;有些动词后常跟动名词作宾语,不能跟不定式作宾语;有些动词后跟不定式和动名词作宾语皆可.* 一般没什么区别，可以互换，但动名词更侧重于表示习惯性动作，而不定式通常表示一次性动作。* 不定式做主语，后面的谓语用单数，动名词做主语也是一样的，但是动名词在句首，也不一定都是做主语，要看情况分析，有时候会是状语从句啊之类的。* 其实没有太大的区别，一般表示泛指意义的行为时多用动名词，但也可用不定式。表具体行为是用不定式，尤其是将来的行为。例如To refuse him is not easy this time 这次拒绝他不是件容易的事情。* 不定式有表达将来的意思。现在分词是对客观事实陈述。* Ⅰ.动名词和不定式做主语的相同点1.不定式短语和动名词做主语时，常常为了保持句子的平衡，用it来做形式主语，如：It is not easy to learn English well.It is no use asking him for help.2.如果主语用了不定式,表语和宾语也要用不定式;主语用了动名词,表语和宾语也要用动名词,这在英语中称为对称性,如:To see is to believe. = Seeing is believing. (眼见为实)It is better to stay home than _A__ out.A. to go B. going C. go D. goneⅡ.动名词和不定式做主语的不同点1.不定式做主语常表示具体的某一动作;表示泛指或一般的抽象的概念时,多用动名词,如:_B_ is a good form of exercise for both young and old.A. The walk B. Walking C. To walk D. Walk2.在”It +be+ no use(good/help/need)”之后常用动名词做主语,而少用不定式,如:It is no use crying over the split milk.It is no help taking this medicine.★但是如果该句型中用了for引出不定式的逻辑主语,就只能用不定式,如:(93) There is no good for us to do that exercise.3.不定式可以和when, where, how, what, whether等连用,在句子中做主语,宾语和表语,而动名词则不能,如:How to solve the problem is a hot potato.Where to put the box seems hard to decide.Whether to do it hasn’t been decided.What to do next is up to you.* 不定式作主语时常用it作形式主语避免句子头重脚轻，保持句子平衡It (形式主语）took me only 20 minutes to finish the job（真正主语）。带有疑问词的动词不定式在句中做主语，其功能相当于名词性从句。Where to hold the singing contest（主语） has not been decided yet.= Where we shall hold the singing contest（主语从句） has not been decided yet.