I used to share a room with my brother/sister when I was young. (share a room)
My uncle has a large house. He lets out one of the rooms to a student. (let out rooms)
Helen promised that she would tidy her room, but she left it in a mess as usual. (tidy your room)
If Martin decides to stay the night, he can sleep in the spare room.
I'd like to book a double / single / twin room.
The seats in the waiting room are hard and very uncomfortable.
Different rooms: the bedroom, the living room / the sitting room, the dining room, the bathroom.