情态动词 专题课件(共28张PPT)

情态动词（Modal Verbs) 情态动词表示说话人对某一动作或状态的态度，认为“可能”、“应当”、“必要”等等。但本身词义不完全，不能单独作谓语动词，必须和不带to的不定式（即动词原形）连用。情态动词没有人称和书的变化。 can and could may and might will and would shall and should must and can’t can and could So he can carry heavy books. ability He couldn't open the door by himself. ability Could you open the door, please? request can and could 1)  表示能力（ability），指有能力做某事，意为“能够”。例如： 注意：表示现在，将来“能够”可用be able to 替换。表示过去“能够”并成功了只能用was/ were able to, 不能用could。例如 My grandma is over eighty, but she can/ is able to read without glasses. We can/ will be able to talk about the matter later. I talked with her for a long time, and at last I was able to make her believe me.(不能用could) can and could 2)  表示请求（request）或（permission)意为“可否”、“可以”。 Could 比can 更有礼貌，在此不是can的过去式。 Can you wait a moment please? Liz, can you do me a favor? Excuse me, could you tell me the way to the station? I wonder if you could help me. (request) ---- Could I use your phone? ----Yes, of course. You can. Do you think I cou