初二下英语知识汇总.docVIP

八年级下·英语知识汇总 Unit1·情态动词should、反身代词 一、情态动词Should 1.定义：should作情态动词，可以表示责任和义务，意为“应当；应该”，可以用于各种人称。 2.用法： 肯定句 主语+should+动词原形+其他 否定句 主语+should not/shouldn’t+动词原形+其他 一般疑问句 Should+主语+动词原形+其他？ 特殊疑问句 （以what为例） What should +主语+动词原形？ You should listen to your parents. You shouldn’t go out last night. Should I take my temperature first? What should I do? 3.近义表达： ought to do 表示“应该；应当” be supposed to do 表示“应该做某事” You ought to diet and take more exercise. They are supposed to shake hands with the guests. 二、反身代词 1.定义：反身代词是表示反射或强调的代词，由第一人称、第二人称形容词性物主代词或第三人称代词的宾格形式的词尾加-self或-selves构成。可译为“本人；本身；自己”。 2.形式： 第一人称 第二人称 第三人称 单数 myself yourself himself, herself, itself 复数 ourselves yourselves themselves Unit2·用could表达建议、动词不定式 一、用could表达建议 用could来表达建议的用法，此时could可以翻译为“可以”，could用于表达建议时语气较委婉，在这里的could不是can的过去式。 You could write him a letter. You could help to clean the park. 二、动词不定式 1.定义：动词不定式的基本形式是“to+动词原形”,否定结构是“not to+动词原形”。动词不定式在句中不能作谓语,其形式不随主语的人称、数和时态而变化。 2.用法： 作主语 To learn English well is very important. = It is very important to learn English well. 作表语 My job is to look after patients. 作宾语 We want to go swimming. 作宾语补足语 She invited me to go to a concert. 作定语 He has too many things to do. 作状语 She got up very early to catch the early bus. 3.“疑问词+不定式”结构 动词不定式可以用在疑问词what、how、when、where等之后，该结构可作主语、宾语、表语等。 作主语：How to get there is a problem. 作宾语：I dont know what to say. 作表语：The question is how to learn English well. *注意：当“疑问词+不定式”结构作宾语时,通常可以和宾语从句进行同义转换。 They are talking about how to get there. = They are talking about how they can get there. 4.常用搭配 （1）有些动词只能跟动词不定式作宾语。如：plan、hope、agree、decide等。 We plan to go climbing. My father agreed to take us to the museum. They decided to join the swimming club. （2）有些动词后要跟动词不定式作宾语补足语。如： want sb. to do sth. 想要某人做某事 tell sb. to do sth. 告诉某人做某事 encourage sb. to do sth. 鼓励某人做某事 warn sb. to do sth. 警告某人做某事 ask sb. to do sth. 请求某人做某事 advise sb. to do sth. 建议某人做某事 Unit3·用could提出请求、征求许可、while的用法 一、情态动词Could 1.用could提出请求 常见的结构是“Could you（please）…？”,意为“你能…吗?”或“请你…好吗?