知识梳理 一、助动词 (一概说 助动词不能单独作谓语,本身没有词义,也不表示动作,只能和主要动词一起构成谓语,表示否定、疑问、时态、语态或其他语法关系. 助动词的分类及其变化形式: 助动词Be Have Do Shall Will (二助动词的用法1.助动词be有八种形式 原形 现在式第一人称单数I 现在式第三人称单数he, she, it 现在式第二人称单、复数和第一、三人称复数 you, we, they 过去式第一、三人称单数I, he, she, it 过去式第二人称单、复数和第一、三人称复数 you, we, they现在分词过去分词
变化形式 am, are, is; was, were; been, being has, had, having does, did; done, doing should would 肯定式be am is are －were being been 缩略肯定式 －‘m‘s‘rewas －－－ 否定式－am not is not are not was not were not not being not been 缩略否定式 －‘m notisn't/'s not aren't/'re not wasn't weren't －－
(1与现在分词构成各种进行时态以及与have和现在分词构成完成进行时态. You are working hard today.你们今天干得很努力. Is Su Ming working this week?本周苏明上班了吗? What have you been doing these days?这几天来你在干什么? (2与过去分词构成被动语态. A new computer has been bought by the office.办公室已购买了一台新电脑. He was been invited to teach at a university there.他被邀请在那儿的一所大学任教. Such books are written for children.这种书是为儿童写的. (3与形容词、名词、代词、从句等构成“系＋表”结构. My job is very interesting and I like it very much. But sometimes it's boring. 我的工作很有趣,我非常喜欢它,可有时候也令人烦. (4与动词不定式构成谓语. The new text seems to be easy, but actually, it is rather difficult.这篇新课文好像很容易,其实相当难. These books are not to be taken out of the room.这些书不得带出室外. 2.助动词have有五种形式 原形 现在式第三人称单数 过去式现在分词过去分词 肯定式have has had having had 缩略肯定式 ‘ve‘s‘d－－ 否定式haven't/'ve not has not had not not having － 缩略否定式have not hasn't/'s not hadn't/'d not －－ (1与过去分词构成各种完成时. We've known each other since 1987.我们从1987年起就互相熟悉了. He's been to Shanghai.他去过上海. We have not seen each other since I left Beijing.自从我离开北京,我们就没见过面. By the end of last month, we had studied English for two years.到上月底,我们已经学习了两年英语了. (2和动词不定式连用构成谓语,表示因客观环境促使不得不做的事. The bus has left, and if we want to catch the train, we'll have to take a taxi. 公交车开走了,假如想赶上那趟火车,我们不得不打的. 点拨 have还可用作实义动词,表示“有”“吃”等含义. Would you like to have some beer?你想喝点啤酒吗? We're having breakfast.我们正在吃早饭. 3.助动词do有三种形式 原形 肯定式 do 否定式 do not 缩略否定式 don't
