Need to tell your teacher, supervisor, or the Italian prime minister to do something? Use the subjunctive form of the verb to form the formal commands. The table below contains some examples of formal commands.
FORMAL COMMANDS
INFINITIVE
LEI
LORO
cantare
Canti!
Cantino!
dormire
Dorma!
Dormano!
finire
Finisca!
Finiscano!
parlare
Parli!
Parlino!
partire
Parta!
Partano!
pulire
Pulisca!
Puliscano!
scrivere
Scriva!
Scrivano!
vendere
Vendano!
Some of the verbs have irregular stem changes in the io form. Sometimes, this form is used to construct the imperatives of Lei and Loro.
FORMAL COMMANDS: VERBS WITH STEM CHANGES
INFINITIVE
PRESENT-INDICATIVE FORM OF IO
IMPERATIVE FORM OF LEI
IMPERATIVE FORM OF LORO
andare (to walk)
vado
Vada!
Vadano!
apparire (to appear)
appaio
Appaia!
Appaiano!
bere (to drink)
bevo
Beva!
Bevano!
cogliere (to pick, to pluck)
colgo
Colga!
Colgano!
dire (to say, to tell)
dico
Dica!
Dicano!
fare (to make)
faccio
Faccia!
Facciano!
porre (to place, to put down)
pongo
Ponga!
Pongano!
rimanere (to stay, to remain)
rimango
Rimanga!
Rimangano!
salire (to climb)
salgo
Salga!
Salgano!
scegliere (to choose, to pick)
scelgo
Scelga!
Scelgano!
sedere (to sit down)
siedo
Sieda!
Siedano!
suonare (to play a musical instrument)
suono
Suoni!
Suonino!
tradurre (to translate)
traduco
Traduca!
Traducano!
trarre (to draw, to pull)
traggo
Tragga!
Traggano!
udire (to listen)
odo
Oda!
Odano!
uscire (to exit)
esco
Esca!
Escano!
venire (to come)
vengo
Venga!
Vengano!
Finally, some verbs have irregular formal command forms that are not based on any present-indicative forms, and which you will have to memorize. These verbs are listed below.
FORMAL COMMANDS: IRREGULAR VERBS
INFINITIVE
LEI
LORO
avere
Abbia!
Abbiano!
dare
Dia!
Diano!
essere
Sia!
Siano!
sapere
Sappia!
Sappiano!
stare
Stia!
Stiano
Note that the same form of the verb is used for the negative formal commands.
From:https://www.dbfei.com/Article/yidaliyu/201311/7689.html