SYNTAX:
sit [on|in|at] <object>
lie [on|in|at] <object>
stand [on|in|at] <object>
get off [of] <object>
Furniture, in this case, refers to any and all objects which can be sat upon or otherwise inhabited by your character. You will be described as sitting, lying down, and so forth in the room's object list, and the room's brief description will change to read where you have decided to take a rest. You will automatically get off of furniture if you begin to move in any given direction.