I heard a sentence the other day, when watching ‘Elizabeth R’ (1971), starring Glenda Jackson. When Elizabeth catches smallpox and her doctor tells her, she gets angry and shouts:
'You lying knave! Telling me I have the small pox when it is nothing but a simple chill!?
Why is when used and not while
I also heard another sentence on TV. It went as follows: ‘Why would you go and have a drink in that café when you have one of your own?’ (I don’t know if this is correct).
Would you be so kind as to explain the difference between ‘when’ and ‘while’ and give a few more examples?
They are often interchangeable. I think “when” is better in both of your examples. “While” would be acceptable but far less common in conversational English.
To get more nit-picky:
It depends on whether you want to focus on a condition or an action. “While” focuses more on an action, especially when the action is ongoing.
“While walking, I saw a hawk.”
During the time that I was walking…
“I listened closely to the sax part while the band was playing”
The band playing is an ongoing action.
" Telling me I have the small pox when it is nothing but a simple chill!"
The focus here is on the condition of having small pox, not the action of “having” small pox.
" Why would you go and have [A] drink in that café when you have one of your own?"
This is focused on the condition of owning a cafe, not the action.