Trundle bed:
Sofa bed:
A
trundle bed or a
sofa bed can also be called a
hideaway or
hideaway bed. Hideaway is also more general in that it encompasses other unique designs, such as this bed that folds up against the wall:
As far as bed sizes go, you have (from smallest to largest): single bed, double bed, queen(-size) bed, king(-size) bed, California king (longer than a king). At least that's the way it is in the US of A.
guardar cama = to stay in bed
estar encamado = to be bedridden
el que con niños se acuesta, "mojao" se levanta <= never heard that