1. need to 作情態(tài)動(dòng)詞,有need do ,相當(dāng)于need to do,通常用于疑問(wèn)句、否定句、條件句、 whether(if) 名詞從句或含否定意義的句子中. 如：
I do not see why we need discuss it further.
我看我們沒(méi)有必要討論下去了.
That's all settled. It needn't be talked about.
那已全部解決了,沒(méi)有必要再說(shuō)了.
He asked me whether he need attend the meeting?
他問(wèn)我他是否有必要出席這次會(huì)議?
2. need 又是實(shí)義動(dòng)詞,各種變化和用法與普通實(shí)義動(dòng)詞相同. 有need to do ,表示“需要去做什么（還未做）”
如：
They need a rest after a long walk.
長(zhǎng)距離行走后他們需要休息一下.
I need you to work for me, young man!
小伙子,我需要你為工作.
3. need 接動(dòng)名詞主動(dòng)形式,表示被動(dòng)意義、這時(shí)動(dòng)名詞和主語(yǔ)之間有動(dòng)賓關(guān)系,釋為“…需要/有必要被…”,need doing 可轉(zhuǎn)換為 need to be done 結(jié)構(gòu),意思相同.如：
My hair needs washing badly. (= My hair needs to be washed badly.)
我的頭發(fā)非常需要洗一洗.
The garden needs watering. (=The garden needs to be watered.)
花園需要澆水.