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.）
阿富汗小海参
