一、While作為并列連詞,意思為“而,然而”,表前后意義上的對比或轉(zhuǎn)折。
例如：There’s plenty of rain in the southeast,while there's little in the northeast.東南部雨量充足,而西北部則很少下雨。
Some people waste food while others haven't enough.有些人浪費糧食,然而有些人卻吃不飽。

二、另外while還有別的用法，while引導(dǎo)狀語從句,有以下兩種含義：
1．表示某個動作正在進(jìn)行的同時,另一動作也在進(jìn)行之中,這時主從句都用進(jìn)行時態(tài),有對同類的兩個動作進(jìn)行對比的意味.如：
While I was playing the piano,she was dancing．我在彈鋼琴,她在跳舞.
While Jim is picking apples,Kate is carrying apples to the truck．吉姆正在摘蘋果,凱特正在把蘋果搬到卡車上去.
2．表示某個動作正在進(jìn)行時,又發(fā)生了另一動作（該動作用一般過去時）.如：
While I was reading,I fell asleep．我讀著讀著就睡著了.
While we were swimming in the river,we saw a fish jump out of the water．我們正在河中游泳時,看見一條魚躍出了水面.

三、while還有以下幾種常見用法：
1．只要（＝as long as）
There will be life while there is water and air．只要有空氣和水,就會有生命.
2．而；然而〔表示對比〕
He is a driver while I'm a teacher．他是司機(jī),而我是老師.
3．雖然（＝although）；盡管〔表示讓步〕
While I see what you say,I can't agree with you．雖然我能理解你說的話,但是我不能同意你.
4．用作名詞,表示“一會兒或一段時間”,常與a,the或this等連用.如：
Just wait a while and then I will help you.等一下,我會來幫你的.
Where have you been all this while?這一陣子你一直都在哪兒?

四、while所引導(dǎo)的時間狀語從句中的謂語動詞只能是延續(xù)性動詞。
例如：I met with an old friend of mine while(when) I was walking along the street.