“need”雙重角色的用法及其區(qū)別
“need”既可以作情態(tài)動(dòng)詞,也可以作實(shí)義動(dòng)詞,但是它們的用法不同.
作為情態(tài)動(dòng)詞的“need”的用法與其他情態(tài)動(dòng)詞“can”,“may”,“must”的用法基本相同：在限定動(dòng)詞詞組中總是位居第一,沒(méi)有非限定形式,即沒(méi)有不定式、-ing分詞或-ed分詞等形式；第三人稱單數(shù)現(xiàn)在時(shí)沒(méi)有詞形變化；情態(tài)動(dòng)詞之間是相互排斥的,即在一個(gè)限定動(dòng)詞詞組中只能有一個(gè)情態(tài)動(dòng)詞.下面是“need”作為情態(tài)動(dòng)詞的用法：
一、need表示“需要”或“必須”,通常用于否定句和疑問(wèn)句.例如：
1．You needn't do it again．你不需要再做了.
2．He needn't worry about it．這件事他無(wú)需擔(dān)心.
3．Need he do this homework first?他需要先做這些作業(yè)嗎?
4．Need they fill in the form?他們需要填表嗎?
二、在否定句中,可以用need的否定形式＋不定式完成體.例如：
1．We needn't have worried．其實(shí)我們不必要慌.
2．You needn't have mentioned it．你本來(lái)不必提起這件事.
3．You needn't have said that when he asked．當(dāng)他問(wèn)的時(shí)候,你其實(shí)不必要說(shuō).
三、needn't后的不定式間或也能用進(jìn)行式或被動(dòng)語(yǔ)態(tài).例如：
1．He needn't be standing in the rain．他不必要站在雨中.
2．We needn't be waiting in this place．我們不必要在這兒等.
3．The hedges needn't be trimmed thisweek．本周樹蘺不必要整修.
“need”作為實(shí)義動(dòng)詞時(shí),通常用法是：
人＋need ＋to do
物＋need ＋doing
物＋need ＋to be done
另外,“need”后還可以直接跟名詞.請(qǐng)看下面的例子：
1．We need to collect the parcel before we leave for England．去英國(guó)之前,我們需要收拾好行李.
2．We need to tell him the truth．我們需要告訴他真相.
3．My car needs repairing．我的汽車需要修理.
4．The flowers need watering．這些花需要澆水.
5．His leather shoes needs to be mended．他的皮鞋需要修補(bǔ).
6．Her room needs cleaning．她的房間需要打掃.
7．It is aquestion that needs very careful consideraton．這是一個(gè)需要慎重考慮的問(wèn)題.