高中英语情态动词详细讲解及例句.doc

一、情态动词无人称和数的变化,不能单独做谓语,只能和行为动词或状态动词构成谓语二、情态动词分为:情态助动词: can(could) 、 may(might) 、 must 、 have to (had to)、 ought to、 shall(should) 、 will(would) 12个半情态助动词: dare 、 need 、 used to、 had better 、 would better(5 个) 三、情态助动词 and could 1)ability : be able to do /manage to do/eed in doing sth. army can defeat their enemy. army is able to defeat their enemy. army eed in defeating their enemy. 2)permission: I smoke here? can ’t smoke here. 3)possibility: 用在否定句、疑问句、感叹句中- can ’t be done by him. 当被用在肯定句中时,表达的是理论上的可能性,不涉及是否真的会发生 expert drives can make mistakes. 要表达现在或者将来的可能性,用 may /might 或 could. may leave for Beijing next month. 但在特殊疑问句中,或与副词 hardly 、 only 等连用的陈述句中表达可能性只用 can/could can the noise ing from? can hardly be the postman,es only in the morning. 4) 有时会: the road can be blocked. 5)could 表示轻微的怀疑或委婉的看法 I’m sorry I couldn ’t lend you the book now. His story could be true,but I hardly think it is. 6)could 表示委婉的请求,主要用于疑问句,不用于肯定句 Could you lend me some money? Yes,I can /No,I am afraid not. 7)could 的常用结构: could+ 动词+ 比较级“非常,再..... 不过了” It couldn ’t be better. Couldn ’t+ 过去分词+ 比较级“非常,再..... 不过了” They couldn ’t have tried harder to make me eel e. Can ’ t..too..=can never too “无论怎样... 也不为过,越... 越好” I can ’t thank you too owe my progress to you. Can ’t (help/choose) but do/can but + 动词原形“不得不,只好” We can but agree wi