（8）不定式的替代。 多用在同一句或联系紧密的对话中，为了避免重复，作宾语或主补，宾补的不定式再次出现时，to后的内容常承前省略（只保留to即可）。但如果承前省略的不定式有助动用的have或be任何形式，后应该保留原形be或have。如： Susan is not what she used to be. —You came late last night. You ought to have finished your homework. —I know I ought to have. 常见的有：I’d like / love / be happy to. 3、动名词复习中应注意的几个问题 （1）动名词作宾语。 ①下列动词后只能接动名词：suggest, finish, avoid, stop, can’t help, mind, enjoy, require, practise, miss, escape, pardon, advise, consider, imagine, keep, appreciate, eacape, permit。 ②下列动词短语接动名词：leave off, put off, give up, look forward to, feel like, have trouble / difficulty(in) doing sth. devote to, get used to, pay attention to, be fond of, be worth。 ③介词后要接动名词。what about、how about、without、be fond of、be good at等介词后接动名词。注意on / upon doing sth. = as soon as 引导的从中。作此意讲时on / upon后也可以接名词。如on his arrival…。 ④动名词作宾语和动词不定式作宾语的区别： 第一组：begin, start, continue, like, love, dislike, hate, prefer, can’t stand 例句：It began to rain. It began raining. It was beginning to snow. I love lying (to lie)on my back. I like listening to music, but today I don’t like to. I don’ t prefer to swim in the river now. 解析：意思无差别，但谓语动词用进行时，后面只跟不定式。 表示一种倾向多接动名词作宾语，如果表示某一特定的或具体的行动，多接不定式。 第二组：remember, forget, regret, try 例句：I remember to meet her at the station. I remember seeing her once somewhere. I forgot giving it to you yesterday. I forgot to tell you about it. Now here it is. I regret not having working hard. I regret to hear of your sister’s death. Try knocking at the back door. We must try to get everything ready. That will mean flooding some land. I had meant to go on Monday 解析：remember to do sth.记住要做的事 remember doing sth.回顾过去发生的事 forget to do sth.忘记要做的事 forget doing sth.忘记做过的事 regret to do sth.对将要做的事抱歉 regret doing sth.对发生过的事后悔 try to do sth.设法……，试图 try doing sth.试试看，试一试 mean to do sth.打算做……，想要 mean doing sth.意味着，就是 第三组：want, require, need 例句：These desks need repairing. These desks need to be repaired. The patient required examined The patient required to be examined. 解析： need doing 需要被做 need to be done需要被做 want doing want to be done require doing require to be done 4、分词复习应注意的几个问题 （1）现在分词在句中作时间、原因、伴随、条件、结果等状语。 ①时间状语（分词作状语前面可加when, while等） Hearing the good news, he jumped with greatjoy. Not having finished her work in time, the boss fired her. ②原因状语 Seeing nobody at home, he decided to leave them a note ③伴随状语 The girls came in, following their parents. ④结果状语 The poor old man died, leaving nothing to his children. 注意：现在分词作状语的几个特性。①时间性。与谓语动词同时发生，用一般时，如发生在谓语动作之前时则用完成式having done。②语态性。与句子的主语之间的关系，是主谓关系或动宾关系。遵循的规则“主动进行，被动完成”。③人称一致性。分词的逻辑主语就是句子的主语。 （2）分词作表语。 S. + be + 动词-ed表示被动，主语是人；S. + be + 动词-ing表示主动，主语是物。分词作宾补不定式作宾补的区别： 5、复习过去分词应注意的几个问题 过去分词作状语，相当于一个状语从句，有来说明原因、时间、条件等。 （1）过去分词作原因状语 Tired by the trip, he soon feel asleep. = Because he was tired by the trip, he soon fell asleep. Lost in thought , he almost ran into a car. =As he was lost in thought, he almost ran into a car. （2）作时间状语 Seen from the hill, the city looks like a garden. =When the city is seen from the hill, it looks like a garden. （3）作条件状语 Given more time, I would have worked out the problem. =If I have been given more time, I would have worked out the problem. （4）伴随状语 The teacher came in, followed by some students. =The teacher came in and was followed by some students. 分词短语作状语时，通常与主句中的主语在逻辑上一致，但有时它也可以有自己独立的逻辑上的主语，这种结构称为独立主格结构。如： Her grandfather being ill, she had to stay at home looking after him.