Por favor, silencio.. with an accent over the o. This is asking politely for silence. Your say Callete! for a command"to Shut It!" This is rude to say, and should be avoided, because it refers to the mouth as "a trap."
Callate, tu tampoco sabes.
'quiet' = tranquilo (pronounced 'trangKEElaw')
"tranquilo" means "calm/quiet" in Spanish
Baje su voz!
Callate, tonto. : Be quiet, idiot. This is rude to say though.
callado
Silencio
Silencio, por favor. Tranquilo, por favor. Podrías guardar silencio, por favor?
'Opposite' is 'Opuesto' in Spanish.
To say "be quiet" in Polish, you can say "Bądź cicho."
its muy tranquilo
The Irish for quiet is "ciúin".