I would be grateful if you answered my questions:
1)This a sentence form my grammar book ,
I was washing my hair when the telephone rang.
If the above is corect why
I was watching tv when my sister talked on the phone.
2)What is the difference between the sentences below?
a) I was watching TV while my sister was talking on the phone.
b)I watched TV while my sister talked on the phone.
1- phone rang = short action my sister on the phone = longer action
2 Both are fine.