一、should 何时省略 (1)在表示建议,要求,命令,想法的动词后的从句里, 用 should + 动词原形, should 可以省略. 如 advise, agree, command, decide, demand, determine, grant, indicate, insist, order, prefer, propose, request, require, stipulate, suggest, urge, vote.常考到的是: suggest, advise, demand, require, propose, insist, order, request. 例子:His doctor suggested that he (should) take short leave of absence. The author proposed that TV (should) be turned off at least one hour every day. 2. 在表示建议,要求,命令,想法的名词后的从句里, 用 should + 动词原形, should 可以省略. 如 advice, decision,agreement, command, decree, demand, determination, indication, insistence, order, preference, proposal, request, requirement, stipulation etc. 例子:It was Bill’s suggestion that everyone (should) have a map. His suggestion was that everyone (should) have a map. He gave us a suggestion that everyone (should) have a map. 3. 在 It is/was +形容词后的 that 从句中用 should 的结构, should 可以省略. 这类形容词常见的有: advisable, anxious, compulsory, crucial, desirable, eager, essential, fitting, imperative(绝对必要), impossible, improper, important, natural, necessary, obligatory, possible, preferable, probable, recommended, urgent, vital etc. 例子:It‘s natural that she (should) do so.It is essential that we (should) tell her the news. 4. 在 lest 和 for fear that(以免),in case(以防)从句中用 should, should 可以省略. She walked quietly lest she (should) wake up her roommates. Have your gun ready in case we should need it. 二、to have done 和 having done 的用法分析 to have done 一般指尚未完成的完成时,属于完成时语态,而 having done 强调时间上的先后顺序,一般作状语。加 doing 一般表示正在做,或者是想待会做,而加 to do 表示想做,但可能做不了。这个要看具体语境。 doing 现在分词;having done 现在分词的完成式,强调分词动作先于谓语动作发生。to do 不定式一般式;to have done 不定式完成式,表明不定式动作先于谓语动作发生。 having done: 完成式;现在分词的完成式;现在分词的完成形式;强调时间 完成式 由于现在分词和动名词都是在动词之后加-ing 构成的,所以两者的被动式 (being done)、完成式(having done)及完成被动式(having been done)是相同的。 现在分词的完成式 现在分词的完成式(having done):表示分词 的动作发生在谓语动词的动作之前.如: 现在分词的完成形式 现在分词的完成形式(having done)现在分词的完成式表示的动作在句中谓语动词动作之前发生,具有主动意义。 强调时间 (for having interrupted 强调 interrupt 这个动词先发生,强调时间 (having done)) 以上两者为时间概念不同,意思相同 -having been done: 完成被动式;完成式;被动语态;被动形式 完成被动式 现在分词和动名词都是在动词之后加-ing 构成的,所以两者的被动式(beingdone)、完成式(havingdone)及完成被动式(having been done)是相同的。 完成式 过去分词短语作状语可分为:一般式(done):表示分词动作与谓语动作同时发生或分词动作发生于谓语动作前;完成式(having been done):强调分词动作发生于谓语动作之前。 被动语态 现在分词一般式的被动语态(being done)表示某被动动作正在进行;现在分词完成式的被动语态(having been done)表示某被动动作发生在谓语动作之前。如: 被动形式 现在分词完成式的被动形式(having been done), 与主语形成被动的主谓关系, 发生在谓语动作之前。 ②独立主格结构 如果分词状语的动作与句子的主语没有逻辑意义的主谓关系, ... -I deny ever having done such a thing.: 我否认做过那样得事情 Now I regret having done that. 我现在后悔这样做了。 have done[口语] 了结,做完,结束(Have done!) 停止!够了!算了吧! Having done their homework, the students played football. 学生们做完作业后,就去踢足球。 What are you most proud of having done? What would you make you even more proud? 你迄今做过的最让你自豪的事是什么?你该做些什么才能让你更为自豪呢? to have done 就是完成时,不过完成时还可以细分为过去完成时,现在完成时,和将来完成时。在下面例句中,We are going to have learnt 9000 words by the end of the next term.就明显是将来完成时