Interested in Language
When I ask someone to come downstairs, can I just say, "Get down!"?
If you want to order someone to come downstairs, you can say "Get down here!" But you better have some degree of authority to "ask" that way.
David, could you come down here please? I need to show you something.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.