while引导的状语从句

注意：（1）注意while的不同含义：a. 表示时间，“当……时；在……同时”；b. 表示让步，“虽然；尽管”；c. 表示转折对比，“然而；但”。（2）while引导的状语从句用一般现在时表示将来的动作或状态。⑦

Eg. While I understand your opinion, I don’t agree with you.

While it’s winter here in our country right now, it’s summer in South Africa.

when引导的句子：

when作连词时，主要义项有：（1）在那时，突然……；

Eg. He was about to tell me the secret when someone patted him on the should.

（2）当……时候；（3）刚（一）……就……；

Eg. I’ll go to see you when you come back.

（4）如果（同if）；

Eg. Call me at once when anything goes wrong with the machine.

（5）可是，虽然；

Eg. She usually walks when she might ride.

（6）既然（同since）

Eg. Why did you write with a pencil when you know you should write in ink?

while引导的状语从句