Unit 3 单元语法小专题(Grammar Focus)-2018年八年级下册英语名师学案（人教版）

单元语法小专题(Grammar Focus) 语法精讲 情态动词could的用法 情态动词具有一定的词义，但不能单独作谓语，只能和动词原形连用作谓语。情态动词没有人称和数的变化。情态动词很多，本单元主要学习could的用法。 1．could是can的过去式，表示过去的能力或某种可能性。对以could开头的一般疑问句作肯定回答和否定回答都用could。 e．g.—Could you play basketball when you were 5 years old？当你5岁时，你会打篮球吗？ —Yes，I could./No，I couldn't.是的，我会。/不，我不会。 —Do you know where Sam is？你知道萨姆在哪儿吗？ —He could be in the school library.他可能在学校图书馆。 2．表示请求的问句 (1)句型“Could you(please)＋动词原形？”意为“请你做……好吗？”，表示礼貌地请求对方做某事，在语气上比can更委婉。肯定回答常用Yes，I can./Yes，sure./Certainly./Of course.等；否定回答常用I'm sorry，I can't./I'm afraid not等。 e．g.—Could you (please) do the dishes？请你洗盘子好吗？ —Sorry，I can't.I have to take the piano lesson.对不起，我不能。我必须上钢琴课。 (2)句型“Could I/we＋动词原形？”意为“我/我们可以……吗？”，表示请求对方允许自己做某事。对这种疑问句的回答比较灵活，但无论是肯定回答还是否定回答，都要避免使用could。肯定回答常用Yes，you can./Yes，sure.等；否定回答常用Sorry./No，you can't.等。 e．g.—Could I borrow your pen？我可以借你的钢笔吗？ —No，you can't.I'm using it.不，你不能。我正在用它。[来源:Zxxk.Com] 【拓展】表示委婉请求的常用句型还有：[来源:学§科§网] Would you like sth./to do sth.? May I do sth.? Shall we do sth.?[来源:学+科+网] Would you mind sth./doing sth.? What/How about sth./doing sth.? 语法专练 一、用所给单词的适当形式填空。 1．Could you __help__(help) me with my lessons? 2．Could you __make__(make) my bed？I'm late. 3．Could you please __clean__(clean) your room? 4．Could we __leave__(leave) at seven? 5．—Could I watch TV now? —Yes，you __can__(could)．[来源:学§科§网Z§X§X§K] 二、单项选择。 (C)6.—Could you please let me go to the movies this evening，Grandpa? —________．But you have to come back before nine. 　　　　　　　　　　　　　　　　 A．Sorry，I can't B．I'm sorry C．Yes，you can D．No，I don't (A)7.Could you please ________ the classroom? A．sweep B．sweeps C．sweeping D．to sweep (B)8.—Could you please walk the dog? —________．I have to do my homework. A．Yes，sure B．Sorry，I can't C．No problem D．Sorry，you can't (A)9.(2018·河北模拟)Could you please ________ it again? A．not do B．not to do C．doing D．does (C)10.—Could I go out with Dave? —________．You have to fold the clothes. A．Yes，you can't B．Yes，I can C．No，you can't D．No，I can't 三、根据汉语意思完成句子。 11．请你帮我扫地好吗？