Question : Are both sentences grammatically correct?If yes,is there a difference in meaning?I read that we can use simple present and present progressive to express future action in time clauses.
a. I'm going to listen to music while I sleep tonight.
b. I'm going to listen to music while I'm sleeping tonight.
They're both correct. There's not much difference between them, but often the use of the progressive form can emphasise duration, though with sleep, which normally has a fairly standard duration, it doesn't make much difference. If you had something like while I wait/am waiting, the difference might be clearer. -)