2023年中考英语二轮复习课件 情态动词

情态动词 什么是情态动词? ·有一定的词义,但不能单独作谓语,必须和行为动词 或系动词连用,构成谓语。 ·无人称和数的变化(除have to区别) ·具有助动词的作用,可用来构成否定句,疑问句及 用于简明答语。 ·后加动词原形 头脑风暴 -快速说出你知道的情态动词! 情态动词 表示推测 can may must 表 示 义 务 should must have to need 表示能力 can could 表 示 建议 had better should 一、表示推测类 She must dislike such a man. How can that be true? The woman in the picture may be her sister. must表示肯定是,用于肯定句 can 表示可能,用于否定句,疑问句 may表示可能,用于肯定句 对一般现在推测 对现在进行推测 对一般过去推测 对过去进行推测 “肯定是” “不可能是” “可能是” must be can’t be may be must be doing can’t be doing may be doing must have done can’t have done may have done must have been doing can’t have been doing may have been doing 两个特殊记忆点: You mustn’t smoke in the hospital. Must I finish the homework now? -Yes, you must. /Yes, you have to. -No, you needn’t. /No, you don’t have to. mustn’t表示禁止。 回答Must疑问句,肯定用must;否定用needn’t 或don’t have to. May I come in now? -Yes, you may. /Yes, you can. -No, you mustn’t. /No, you can’t. may表示请求时,肯定回答用may,can;否定回答用mustn’t 或can’t。 二、表示义务类 Students must finish their homework before class. I have to go now. Children should learn to respect others. I need type this letter before work. I need to type this letter before work. must:必须 have to: 不得不 should:应该 need:需要 need 需要(情态动词、实意动词) have to 不得不 三、表示能力类 I can draw. = I am able to draw. I could ride a bike when I was six years old. can:能,可以,相当于be able to 四、表示建议类 You should see a dentist. You had better not go there by air. =You’d better not… should:应该 had better:最好 五、几组容易混淆的词 must vs. have to I must brush my teeth before going to bed. I have to go to see the doctor. must 强调说话者的主观意愿,无人称,时态的变化;mustn’t表示禁止; have to强调客观上的必要性,常翻译为“不得不”,有人称和时态的变化。 can vs. be able to She can sing the song. Some of the singers were able to sing English songs as well as native speakers. can表示能力,许可,建议,请求和可能性。只有can, could两种形式。 be able to表示在具体某件事上的能力,其形式主要靠be动词来变化,形式比can多。 ought to vs. should Every citizen ought to perform military service. You should not run alongside the swimming pool. ought to侧重于表示按照法律,法规等规定,就强制意义的责任或义务。 should含有个人意见,强调主观看法,语气比ough