"When" can be telic, atelic, semefactive, durative, inchoative... (basically it covers everything in a particular moment or general time frame). "While" is only durative, IE referencing something while its in progress. Any time you use "while" , you can interchange it with "when" (but you can't do it in reverse)

Hi Ming, you can use these words to join sentences. And When (search for the translation to your language) is used to show that an action or something that was happening (past continuos) was interrupted by another thing that happened (past simple), for example: -I was reading a book when you knocked at my door. And you should also know that you can say the same thing by this way: -When you knocked at my door, I was reading a book. Realize that "when" is always used before the past simple, and here you'll see that "while" goes just before the past continuos when we want to join these 2 sentences, for example: -While I was reading, someone knocked at my door. And "While" is also used to describe something that was happening at the same time that another thing. I mean, for example: -You weren't listening to me while I was speaking. And remember, Ming, it isn't bad to make mistakes, sometimes I use the "when", when I should say "while", but it's understood. Sometimes even native speakers do that. So you have to be comfortable and confident about yourself. And another advice: when is used more than while. And as you should know, when is used to make questions about the time of a specific thing, that's way is more often to hear the word "when" than "while". I hope this can help you a lot. If you want to send message, you can. I'd like to practice my english with you, so then I will improve my english and so do you. Nice to meet you. See you later, if you want.

While is used for mainly actions which are process...like I am listening to music while jogging When is used for pointing fixed ones... When do you sleep?...

Hello

Translate this in your native language , this will help you know the difference When I used to do work. While doing my work.