新概念英語(yǔ)第二冊(cè)語(yǔ)法點(diǎn):情態(tài)動(dòng)詞can用法大全

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情態(tài)動(dòng)詞can在英語(yǔ)中的使用頻率較高,主要用法和考點(diǎn)有:
    一、表能力(ability)
    此時(shí),can表示“會(huì),能夠”。否定句直接在can后面加not,疑問(wèn)句則將can提到句首。如:
    肯定句:She can drive a car. (她會(huì)開(kāi)車(chē)。)
    否定句:She cannot/can't drive a car.
    一般疑問(wèn)句及其回答:Can she drive a car? Yes, she can. / No, she can't.
    劃線部分提問(wèn):What can she drive? (假如劃線部分為a car的話)
    【注意】can與be able to
    1、be able to只能表示“會(huì),能夠”,但can還有其他意思,請(qǐng)參考接下去can的其他幾種用法。
    2、can只有現(xiàn)在時(shí)和過(guò)去時(shí)兩種形式,而be able to則有多種時(shí)態(tài)形式。如:
    Will you be able to come tomorrow? (你明天能來(lái)嗎?)
    This factory has been able to produce newly-devised sewing machines. (這家工廠已能生產(chǎn)新設(shè)計(jì)的縫紉機(jī)了。)
    3、在be able to之前可加用另外一個(gè)助動(dòng)詞,且多用于否定或疑問(wèn)結(jié)構(gòu),而can則無(wú)此用法。如:
    He may be able to come tomorrow morning. (他明早可能能來(lái)。)
    4、用于否定結(jié)構(gòu), be able to表達(dá)一時(shí)情況,而can則表達(dá)往常情況。如:
    He is not able to swim today. (他今天不能游泳。)
    He can't swim at all. (他根本不會(huì)游泳。)
    5、be able to后可接系表結(jié)構(gòu),表示一種狀態(tài)或性質(zhì),而can沒(méi)有這種用法。如:
    He was able to be cold about her now. (他現(xiàn)在對(duì)她可能有些冷淡。)
    6、be able to有非謂語(yǔ)動(dòng)詞形式(即接在動(dòng)詞不定式或是以動(dòng)名詞或分詞的形式出現(xiàn)),而can則沒(méi)有。如:
    I hope to be able to do the work. (我希望能做這項(xiàng)工作。)
    Being able to sing well, he decided to take part in the singing contest. (因?yàn)樯瞄L(zhǎng)唱歌,他決定參加歌唱比賽。)
    He left the classroom sadly, without being able to answer six of the questions of the test. (他難過(guò)地離開(kāi)了教室,有六道題沒(méi)答出。)
    二、表許可(permission)
    此時(shí),can表示“可以”。如:
    Can you lend me a pen? (能借我一支筆嗎?)
    He can leave now. (他現(xiàn)在可以離開(kāi)了。)
    【注意】can與may
    注意對(duì)比:
    Can I help you?
    May I help you?
    may的語(yǔ)氣更加委婉。
    三、表猜測(cè)(guess)
    can如果要表猜測(cè)一定要用否定形式can't,表示可能性比較大的猜測(cè)。如:
    對(duì)過(guò)去時(shí)間:He can't have gone to Paris. I saw him on the street just now. (他不可能已經(jīng)去巴黎了。我剛才在街上看到他了。)
    對(duì)現(xiàn)在時(shí)間:He can't be reading in the library now. (他現(xiàn)在不可能在圖書(shū)館看書(shū)。)
    【注意】can't與must
    can't表示否定猜測(cè),must表示肯定猜測(cè)。如:
    對(duì)過(guò)去時(shí)間:He must have been to New York many times, because he knows it very well. (他一定去過(guò)紐約很多次了,因?yàn)樗麑?duì)紐約了如指掌。)
    對(duì)現(xiàn)在時(shí)間:He must be cleaning the classroom now. (他現(xiàn)在肯定在打掃教室。)
    四、趣味用法
    can有時(shí)也會(huì)用作實(shí)義動(dòng)詞,表示“裝罐”;此時(shí),can也可以作為名詞,表示“罐頭”。如:
    He can can the can he can can.
    這句話乍一看,讓人暈頭轉(zhuǎn)向,但真要看懂,關(guān)鍵在于要明白can可以用作實(shí)義動(dòng)詞和名詞。
    句中的第1個(gè)和第4個(gè)can是情態(tài)動(dòng)詞,表示“可以,能夠”。第2個(gè)和和第5個(gè)can是實(shí)義動(dòng)詞,表示“裝罐”。第3個(gè)can是名詞,表示“罐頭”。而句中the can后面的he can can實(shí)際上是the can的定語(yǔ)從句,省略了that或which。
    所以,原句的意思是:
    他能裝他會(huì)裝的罐頭。