一、 动词不定式

　　1. 不定式可作主语。

　　2. 当不定式的逻辑主语是动作的承受者时， 一般要用不定式的被动式。但是在某些形容词后面， 即使是这样， 也不用被动式。

　　3. 某些动词后面只能跟不定式作宾语。

　　4.当不定式作宾语， 且后面又有宾语补足语时， 通常用it作形式宾语来代替不定式， 而把不定式后置。

　　5. had better, would rather than等词的后面只跟不带to的不定式。

　　6. 动词不定式的一般式表示它与谓语动词同时发生， 或在其后发生； 其完成式则表示动作发生在谓语动词之前。但要注意动词plan, expect, wish, intend, mean, want, would(should) like等后面的不定式的完成式表示原打算要做而最终未做成的事情。

　　二、 动词的-ing形式改错指导

　　以下动词只能跟-ing形式作宾语， 不能跟不定式。如： advise, admit, avoid, allow, consider, delay, enjoy, escape, excuse, finish, appreciate, imagine, include, mention, miss, prevent, quit, resist, risk, stand, suggest, understand等。

　　三、 过去分词改错指导

　　注意下列几组动词的-ing形式和过去分词之间的区别： surprising(令人吃惊的)， surprised(感到惊讶的)； interesting(令人感兴趣的)， interested(感兴趣的)； disappointing(令人失望的)， disappointed(感到失望的)； encouraging(令人鼓舞的)， encouraged(感到鼓舞的)

　　练 习

　　1. I was used to go to the cinema once a week.

　　2. He has never been heard speak ill of others.

　　3. We hear it say frequently that what present-day men most desire is security.

　　4. He always enjoys to read a detective story.

　　5. His father would not let him to go.

　　6. It is difficult to make yourself understand in English.

　　7. You should avoid to keep company with such people.

　　8. Smiling graciously, my offer was accepted by him.

　　9. You had better not to go there.

　　10. The doctor advised me giving up to smoke.

　　注 释

　　1. was used to → used to， used to +动词原形表示过去的习惯， be used to+名词/动名词表示习惯的持续。

　　2. speak → to speak， 感观动词/使役动词改为被动语态时， 要将主动态时省去的“to”还原。

　　3. say → said， said是过去分词作补足语， 而it是形式主语。

　　4. to read → reading, enjoy其后只可加动名词。

　　5. to go → go, let是使役动词， 其后接不带to的不定式作补足语。

　　6. understand → understood, make oneself understood译为“使别人了解自己的意图即自己被别人理解”。

　　7. to keep → keeping， avoid其后加动名词作宾语。

　　8. my offer was accepted by him → he accepted my offer， 分词短语smiling graciously的动作执行者是he， 而不是my offer。

　　9. to go → go， had better其后接动词原形。

　　10.giving up to smoke → giving up smoking, advise sb. to do sth.,而give up其后接动名词或名词。