[Rusty]

Originally Posted by DocMolly

... (I should practice the piano.)

Debe hacer ejercicios todos los días.
(He/She/You/It should exercise everyday.)

¿Cuál libro debo leer?
(Which book should I read?)

Debes cepillarte los dientes dos veces al día.
(You should brush your teeth twice a day.)

Deben limpiarse los dientes con hilo dental una vez al día. (Did you mean to switch person and number?)
(You should floss your teeth once a day.)

Deberías esperar a que él te llame (a ti).
(You should wait for him to call you.)

Te debo una.
(I owe you one.)

No me debes nada.
(You don't owe me anything.)

Ha de haber un restaurante. por aquí.
(There must be a restaurant around here.)

Se hubieran venido a la fiesta. = Ojalá hubieran venido a la fiesta.
(They should have come to the party. = I wish they would have come to the party.)

Welcome to the forums!

I've given you some corrections above.