We grow up hearing negative commands: Don't bother your brother! Don't scream! Don't forget to do your homework! The negative tu command forms of all verbs are formed by the infinitive of the verb preceded by non:
Non andare!
Non avere!
Non dire!
Non fare!
Non mangiare!
The negative voi command forms of all verbs are formed simply by placing non before the affirmative voi form:
Non credete!
Non dormite!
Non fate!
Non finite!
Non parlate!