νέῳ δὲ σιγᾶν μᾶλλον ἢ λαλεῖν πρέπει → it's fitting for a young man to keep silence rather than to speak (Menander)
singular: P. and V. σύ.
plural: P. and V. ὑμεῖς.
you there: Ar. and V. οὗτος σύ, οὗτος.