when既指時間點，也可指一段時間，while只指一段時間。when從句的動作和主句的動作既可以同時也可以先后發(fā)生，while從句的動作和主句的動作必須同時發(fā)生。when引導(dǎo)的時間狀語從句為一般過去時，while引導(dǎo)的時間狀語從句為過去進行時。

1、when例句

When are you going home?

你什么時候回家?

When eating a whole cooked fish, you should never turn it over to get at the flesh on the other side.

吃一整條魚時，切忌把它翻過來去吃另一面的肉。

When I met the Gills, I had been gardening for nearly ten years.

遇到吉爾一家時我已經(jīng)做了近10年的園藝工作。

When he brought Imelda her drink she gave him a genuine, sweet smile of thanks.

當他把飲料拿給艾梅爾達時，她真誠而甜美地向他微笑以示感謝。

I asked him when he'd be back to pick me up.

我問他什么時候回來接我。

2、while例句

They were grinning and watching while one man laughed and poured beer over the head of another.

當一個男人大笑著把啤酒倒在另一個人頭上時，他們都在樂呵呵地看著。

The two ministers have yet to meet, but may do so while in New York.

兩位部長尚未會面，但可能會在紐約碰頭。

Marianne was tempted to turn the large rooms into traditional French-style salons, while Howard was in favour of a typically English look.

瑪麗安娜想把這些大房間弄成傳統(tǒng)法式客廳的樣子，但是霍華德喜歡典型的英式風格。

While the numbers of such developments are relatively small, the potential market is large.

盡管這種增長的數(shù)量相對較小，但是潛在的市場是巨大的。

They walked on in silence for a while.

他們繼續(xù)默默無語地走了一會兒。