Not only commands: the imperative mood or "modo imperativo"

In both languages, an imperative like "Entra!" ( Come in! Go in!) can be a kind invitation or a brisk order, depending on the tone of voice and the situation.

The main difference is that Eng. has the simple verb form for 2nd persons (where "go!" corresponds to It. "vai" sng. and "andate!" pl.) or "let" used as an auxiliary, especially as "let's" for the 1st pers. pl.
It., instead, has five different verb forms (for each of the three conjugations) for the five persons - the first pers. sng. is not there because I cannot give an order to myself - unless I pretend I'm talking to another person.
If I say to myself "Gianfranco, stai attento!" ( Gianfranco, be careful!) I use the 2nd pers. sng. as if I were talking to a friend.

The negative imperative is obtained with "non" before those forms, except the 2nd pers. sng. that uses the infinitive: "Non andare! Non correre! Non partire!" ( Don't go! Don't run! Don't leave!)

For pronouns affixed to imperatives see