Don't sit in my seat

[Winwin2011]

My kid asked me why we say "Don't sit in my seat" not ""Don't sit on my seat"

Could anybody explain it, please?

Thanks.

 

[Rover_KE]

We use both prepositions. It depends what kind of seat we are referring to.

Usually we sit in an armchair and on a stand chair so if we temporarily vacate the one we have been sitting in/on we would give one or other of the quoted commands.