Types of hotel rooms

single room a room for one person with a single bed (a (bed for one person 

I'd like a double room for my husband and me and a single room for my brother
 

double room a room for two people with a double bed (a (bed that two people can sleep in
My wife and I would like a double room for three nights please

twin room a room for two people with two single beds
My sister and I always book a twin room when we go on holiday together 

family room
a room for parents and children to stay in together; it usually has a double bed and some single beds and sometimes a cot for a baby
 

We'd like to book a family room please. We're two adults, a three year-old and a baby of seven months