What is differences between 'when' and 'while'
When I was reading the book my friend called me.
While I was reading the book my friend called me.

When I was cutting vegetables my sister was watching t.v
While I was cutting vegetables my sister was watching t.v

Is there any differences between both word WHEN and WHILE or I can use any one of them..

Question

What is  differences between 'when' and 'while'
When I was reading the book my friend called me.
While I was reading the book my friend called me.

When I was cutting vegetables my sister was watching t.v
While I was cutting vegetables my sister was watching t.v

Is there any differences between both word WHEN and WHILE or I can use any one of them..

Answer

"While" is used more for some segment of time; "when" is for some point of time.
It's normal to say "while I was cutting vegetables my sister was watching", but if there is used the word "when" then there must be a finished action in the second part of the sentence. For example, "When I was cutting vegetables my sister has finished watching TV".

Answer

In those sentences, they can both be used. But "while" always means "at the same time". "When" can also be used as the question "what time?"

Answer

You can use any of them in this context.