Imperativo/2

Irregular verbs follow the same pattern as regular ones, except for essere, avere and sapere which have irregular forms for the 2nd person singular and 2nd person plural. They are conjugated as follows:

c1 c2
  essere avere sapere
tu sii! abbi! sappi!
voi siate! abbiate! sappiate!

Note that dire has a truncated tu form: di’. The same goes for andare, dare, fare, and stare, but in this case a regular tu form is also possible: va’/vai, da’/dai, fa’/fai, sta’/stai.

c1 c2
dire andare dare fare stare
dì va'/vai da'/dai fa'/fai sta'/stai

Negative imperative corresponds to the forms of the present indicative for the 1st and 2nd person plural (noi and voi). For the 2nd person singular (tu) it is formed by adding non before the infinitive of the verb.

Non andiamo al mare, fa ancora freddo - Don’t we go to the seaside, it is still cold
Non mangiate quella torta, non è buona - Don’t eat that cake, it isn’t good!
Non parlare così piano, non ti sento - Don’t speak so softly, I can’t hear you!