這三個詞都可以用作連詞,，表時間關(guān)系,，常常可以互換,，但又有區(qū)別：

1. while“當（在）……的時候”表主句的動作或事情發(fā)生在從句中的動作或事情的進展過程之中,；簡單地說，就是同時發(fā)生,！while從句里謂語動詞必須是延續(xù)性動詞,，不能是短暫性動詞。從句常為進行時態(tài),。

He slept while/when I cooked supper. 我燒晚飯時,，他睡覺,。

You can do the dishes while/when she cooks dinner. 她燒飯時你可以洗洗碗。

While/When she was in Australia, she met a rich businessman and fell in love with him.

在澳大利亞時,，她遇到了個富商并墜入愛河,。

Please don't talk so loud while others are working. 別人在工作的時候,，請勿大聲講話。

注：（從句是進行時,，多用while,，也有人用when）

Cathy broke her arm while she was playing in the garden.

凱茜在花園里玩的時候摔傷了胳膊。

While they were having a nap, somebody broke into the house.

他們在午睡時，有人闖進他們家,。

While he was watching TV, I was working. 他看電視的時候,，我在工作。

注：（主句從句都是進行時,，一般只用while,，不用when，尤其是考試時?。,。。?/strong>

2. when“當（在）……的時候”主句和從句的動作或事情可以同時發(fā)生,，也可以先后發(fā)生,。when從句里謂語動詞必可以是延續(xù)性動詞，也可以是短暫性動詞,。

I was having a bath when the telephone rang.電話鈴響的時候我正在洗澡,。

She was waiting for a bus when the accident occurred.

車禍發(fā)生時她在等公交車,。

I always wear gloves when I wash clothes.

我總是戴著手套洗衣服,。

She always takes her cellphone when she goes out.

她出門總帶著手機,。