Modal VerbModal VerbCan (could) , may ( might), must (must), have to (have got to), shall (should), will (would), need (need) , ought to , dare ( dared)1. can, could , be able toMan cannot live without air.I’ll not be able to come this afternoon.I can’t come this afternoon 以下情况只能用 be able to. 不能用 could.He was able to swim half-way before he was wore out.( 经过一番努力才完成的事） He was able to go to the party yesterday evening客观主观（ can) ( 主观，而且“某件事已成功” ) This cannot be done by him.How can you be so careless!How (who )can tell….惊异，怀疑，不相信（否定，疑问，感叹句）Could I come to see you tomorrow? ( 表语气） Yes ,you can. / No, I’m afraid not.表推测，猜测。S+can/ could+ not +v Can/ Could+ s+ vCan this news be true? ( 对现在状态的推测）The man can’t be our new teacher.S+ can/ could +not be +v-ing Can/could+s+be+vingHe can be reading in the room,for I saw him in the street just now. （对现在动作 的推测）It’s too late.Can they be doing the experiment?S+can/could +not have +done Can/could+s+have doneThe road isn’t wet.It couldn’t have rained last night.She didn’t call me yesterday.Could she have forgotten my number? ( 对过去事实的推测）may might 表示请求，许可May I use your pen? Yes,you can (may) / Sure / of course / No,you can’t / No, you mustn’t ( 语气强） No, you’d better not Please don’t / I don’t think you can 表示推测May be / Might be (may 的可能性比 might 大）May be doing/ Might be doing ( 对现在动作推测） She may be our new teacher. Is she?May/might +have doneMay you succeed ( 表祝愿）…….that….. so that…… + may/might v…. in order that…He wants to take a taxi that( so that/ in order that)he may get there in time.May I….? No, you may not ...
