[Grammar] Is anybody or does anybody?

[goldenace]

Are the phrases "is anybody" and "does anybody" used differently in terms of context? Can they be used interchangeably?

Such as:

Excuse me. Does anybody sit there? / Is anybody sitting there?

I know that one is used with present simple and the other with present continuous but which is more suitable?

 

[Grumpy]

"Is anybody sitting here?" refers to the present moment only. You are asking if someone has temporarily vacated that place, or if that place is being reserved for someone at the present time.
"Does anybody sit here?" refers to a continuous process, including the past. You are asking whether or not a specific place is normally occupied by someone.