Unit 2 sporting events單元學案

all the children were involved in the school play.所有的孩子都參加了學校排練的劇。this lesson involves a lot of work.這一課需要做的工作有很多。語法點津             情態動詞    所謂情態動詞是指它含有一定的含意.可以表達某種感情和說話的口氣，但是它不可以單獨使用作謂語動詞。  情態動詞有：can(could)，may(might)，must(must)，have to，shall(should)，will (would)，need(need)，dare(dared)，ought to情態動詞無人稱和數的變化.不能獨立使用；它與其后面的動詞原形合成謂語。情態動詞的具體用法如下：  (一)can和could的用法  1.表示能力或客觀可能性，還可以表示請求和允許。例如：  can you finish this work tonight?  man cannot live without air.  can i go now?  yes，you can.  ① could也可表示請求。語氣委婉.主要用于疑問句.不可用于肯定句，答語應用can(即：could不能用于現在時態的簡略答語中)。例如：    could i come to see you tomorrow?    yes, you can(否定答語可以用no, i’m afraid not).   ② can表示能力時，還可用be able to代替。例如：    i’ll not be able to come this afternoon.can只能用于一般現在時和一般過去時(could)的句子中，be able to可以用在任何時態中,另外can只表明具備某種能力.但不一定做了，可be able to 不僅具備了某種能力.而且還實際實施了。2. 表示驚異.懷疑，不相信態度。（主要用在否定旬、疑問句或感嘆句中）    can this be true? how can you be so careless!    this cannot be done by him. 3. can (could)+have+過去分詞”的疑問或否定形式表示對過發生的行為懷疑或不肯定。例如：    he cannot have been to that town.  can he have got the book'?  注意：can 習慣用法：①  cannot but不得不  i cannot but admire his courage.我不得不佩服他的勇氣。 ② cannot (couldn't) help + doing 情不自禁；如：   when i heard what the little girl said i couldn’t help laughing.當我聽見小女孩所講的，不禁大笑起來。③ can but只好，不得不    we can but agree with him.我們只好同意他。④  cannot ...too...怎么……也不過分  you cannot be too careful in the choice of your friends.你在選擇朋友時，怎么小心也不過分。    ⑤ 表示經過努力才能完成之事不可用could, 而只可用be able to-如：because he worked hard he was able to pass the exam.⑥ 可表示輕微的懷疑。如：his story couldn't be true but i really think it is.他的故事有可能是真的.但我幾乎不信。well, i couldn't do the job today, but i’d rather put it off until saturday.我今天是可做這件事.但我寧愿拖到周六。