could的否定形式是could not,多缩写为couldn't,两者通常都读作[>kudnt].(1)表示能力,意思是:能,会.【例】Could you speak English then?那时你能讲英语吗?He said he couldn't follow me.他说他跟不上我.注意:①could(能)和was/were able to 都表示过去一般具有某种能力.【例】He could (was able to) swim very well when he was nine.他九岁时就很会游泳.②was (were) able to 可以表示过去某时有某种具体的能力并且实际上可以做到,但could表示过去的习惯能力.【例】Although the driver was badly hurt,he was able to explain what had happened.司机虽受重伤,但仍能说明发生了什么事.(2)表示可能性,意思是:可能.【例】That big cinema can seats 2,000 people.那家大电影院能坐2,000人.He said he couldn't come.他说他不能来.(3)提出请求、疑问或看法(could是虚拟语气,代替can,在时间上与can没有区别,只是语气比can委婉.can语气直爽、肯定).【例】----Could you let me have your passport?----Yes,here it is.—看看你的护照好吗?—行,这就是.(4)表示惊异、不信等情绪(用于疑问和否定句中,此时could与can用法相同,无时间上的差别,用could语气缓和,情绪要弱).【例】Who could have taken them?谁会把它们拿走了呢?She couldn't have left so soon.她不可能这么快就走了.(5)表示与事实相反的情况(用于虚拟语气).【例】How I wish I could go with you!我多么希望和你们一道去!
would的用法1) 用于提出提议或邀请例:Would you like to change a seat?It's warmer here.(您要不要换一下座位?这里暖和些.)Would you prefer a hardback edition?(您要不要买一本精装本?)2) 用于提出客气的要求或请求:例:I would like you to fetch that document for me now.(我想请你现在就帮我把那份文件取来.)I would like to know more about your plan.(我想更多地了解一下你的计划.)3) would you mind + doing句型通常用于表示请求对方做一件有一定麻烦的事情,语气一般都非常客气.注意回答时通常是肯定的,以表示愿意做所要求的事情.例:Would you mind filling in this form?(请您填一下这张表.)Would you mind repeating what you just said?(请把刚才的话重复一遍好吗?)4) 用于委婉地表示自己的意见:例:I would think the journey will take something like two weeks.(依我看,这次旅程大约需要两个星期.)I would look at the problem a little differently.(我对这个问题的看法略有不同.)5) 用于表示过去经常性的行为或动作:例:The retired captain would sit hours on end watching ships sailing past.(退休的船长经常坐在海边观望过往的行船,一坐就是几个小时.)He would go to bed strictly at 9,and on Sundays would not have lunch anywhere except in that restaurant.(他总是严格地9点上床睡觉.星期日总在那家饭店吃午饭.)