Don't!: немој & не + Imperfective

To tell someone not to do something, Serbian has two patterns.

• немој / немојте / немојмо + да + present: Немој да вичеш! (Don't shout!), Немојте да касните! (to several people, or politely), Немојмо да се свађамо! (Let's not argue!). The verb after да shows the person.
• не + imperative: for a deliberate action, use the imperfective verb. If you think of a perfective verb, switch to its imperfective partner: отворити → Не отварај прозор!, купити → Не купуј то!, прећи → Не прелазите улицу!

Warnings about something that could happen by accident keep the perfective: Не заборави кључеве! (Don't forget your keys!), Пази да не паднеш! (Careful not to fall!).