1、when 和 while 的用法和区别while 和 when 都是表示同时，到底句子中是用 when 还是 while 主要看从句和主句中所使用的动词是短暂性动作（瞬时动词）还是持续性动作。1、若主句表示的是一个短暂性的动作，而从句表示的是一个持续性动作时，两者都可用。如：He fell asleep when while he was reading. 他看书时睡着了。 I met him when while I was taking a walk in the park. 我在公园散步时遇到了他。 2、若主、从句表示两个同时进行的持续性动作，且强调主句表示的动作延续到从句所指的整个时间
2、，通常要用 while。如：Dont talk while youre eating. 吃饭时不要说话。 I kept silent while he was writing. 在他写的时候，我默不作声。 3、若从句是一个短暂性动作，而主句是一个持续性动作，可以 when 但不用 while。如：When he came in, I was listening to the radio. 他进来时，我在听收音机。 It was raining hard when we arrived. 我们到达时正下着大雨。 4、若主、从句表示的是两个同时( 或几乎同时 )发生的短暂性动作，一般要用 when
3、。如：I thought of it just when you opened your mouth. 就在你要说的时候，我也想到了。如果是进行时态，一般是持续性的。如果是过去式，一般是短暂性动作。对于，填写 when 还是 while 的问题，通常首先看主句和从句中的时态，再根据以上 4个规律来判断填写那个单词。主句 从句短暂性 when/while 持续性（过去时） （过进：was/were +doing）He fell asleep when while he was reading.持续性 while 持续性（一般现在/过去时） （过进：was/were +doing）Dont tal
4、k while youre eating. I kept silent while he was writing. （现进：am/is/are +doing） （现进：am/is/are +doing）（过进：was/were +doing ） （过进：was/were +doing）I was watching TV while My mother was cooking (动作同时发生)持续性 when 短暂性（过进：was/were +doing ） （过去时）I was listening to the radio When he came in.短暂性 when 短暂性（过去时） （
5、过去时）I thought of it just when you opened your mouth.用 when 或 while 填空1_ Tom was eating supper, it began to rain outside.2 Dont use your phone_ you are driving a car.3 What were you doing _ Mr. Zhou came in ?4 Jim is good at math _ Mary is good at English.5 We were watching TV _ the electricity was o
6、ff6 _Peter was sleeping; a thief broke into his house.7 It snowed _ we arrived in Tokyo.8 She left her hometown_ she was five.9 I was studying in the library_ the UFO landed选用 when 或 while 填空。1. My wallet dropped on the ground_ I was walking.2. _ I was falling asleep there was a loud knock on the do
7、or.3. _ he was reading, the telephone rang.4. Were the students listening to the teacher carefully _ the teacher was giving a lesson?5. _ the telephone rang, I was doing my homework.6. Was she playing games _ the bell was ringing?7. The days get longer _ spring comes.8. Lucy was listening to the rad
8、io _ Lily was watching TV.9. _ we were batting on the lake, we saw a fish jump out of the water.10. They have their PE lesson indoors _ it rains.用 when, while 填空：1. I was listening to the radio _ he came in.2. _ the teacher came in, we were talking.3. _ he came back, I was doing some washing.4. I was cooking dinner _ they came home.5. He fell asleep _ he was reading.6. He asked me a question _ I was speaking.7. Jim hurt his arm _ he was playing tennis.8. _ she was waiting for the train, she became very impatient.9. He was watching TV _ she was cooking.
