语法动词之系动词，助动词，情态动词讲解及练习（讲义）通用版英语六年级下册

系动词、助动词、情态动词 一、系动词的概念:系动词，也称联系动词。它本身有词义.是用来辅助主语的动词，不能单独用作谓语.其后必须跟表语.构成系表结构说明主语的状况、性质、特征等情况。 最常见的系动词是be动词。 1、系动词的分类: （1）.状态类系动词(表示主语状态): be （2）感观类系动....起来是: sound, taste, smell, feel （3）变化类系动词(表示主语变成什么样): get, fall, grow, become （4）持续类系动词(表示主语继续或保持一种状况): stay, keep, stand, rest （5）表象类系动词(表示看起来).... see, appear （6）终止类系动词(表示主语已终止动作): prove, turn out 2、系动词的用法be的三种形式: am, is, are （1）如果主语是第一人称1时，be用am。 I am a student.I am ten years old. （2）如果主语是you或者复数形式时，be动词用are。 You are a good boy. They are in the same school. （3）如果主语是单数名词、不可数名词或he,she,it时，be动词用is。 The picture is beautiful. The bread is delicious. He is a middle school student. 3、肯定句变否定句:在be动词后加not。 I am a student. -- I am not a student. 4、陈述句变疑问句: (1) be动词放在主语前(一、二人称要互换)。 (2)疑问词(+名词) + be动词+表语? 疑问词(+名词)+一般疑问句? My name is May. -- Is your name May? -- What's your name? 二、助动词:一般无实际意义，只是帮助动词构成谓语。 常用助动词: be, have, has, do, does, shall, did, will, should, would等。 1.表示时态 He is singing. She has got married. 2.表示语态 He was sent to America. 3.构成疑问句 Do you like noodles? 4.构成否定句 Did you go to Hong Kong 5.加强语气 He did know that. 三、情态动词: 概念：用来表示说话人的某种感情或语气的词，叫情态动词 1.may :表示许可、可能性 May I come in?(表示许可) It may be right.(表示可能性) 2.can:表示能力、允许与可能性 1 can sing and dance.(表示能力) Perhaps he can help me. (表示可能性) You can use my bike.(表示允许) 3.情态动词有自己的词义，但是不能单独作谓语 She can sing well.谓语是can sing. 4..情态动词没有人称和数的变化，有过去式.但无分词形式。 1/ You/ He / She can swim. 5..情态动词之后只能跟动词原形(ought除外)。 We must study hard. I couldn't walk when I was a baby. 6. may引导的疑问句 肯定回答: Yes, you may. 否定回答: No, you mustn't. / No, you can't. / No, you may not. 例:-May I come in? - Yes, please / No, you mustn't. 7. must构成疑问句 回答的否定形式经常是needn't或don't have to,意为“不必要”，而不说mustn't，除非特别强调。 - Must I hand it in before five o'clock? - Yes, you must. / No, you needn't. 练习题 一、单选题 1．Where ______ my books? (    ) A．is B．are C．am 2．There ________ thirty balls in the box. (     ) A．am B．is C．are 3．—What _______ these? They’re yellow. (     ) —They’re tomatoes. Try some, please. A．is B．am C．are 4．The hot