El presente de subjuntivo in the imperative?
In the imperativo afirmativo, the 2nd person singular and 2nd person plural are NOT formed with the subjunctive, but have their “own” pattern.
However, with the imperativo negativo, all forms are formed with the subjunctive, right?
Right. Only the chasing 2nd person knows a real imperative in the sense of his own conjugation. Another exception: there is no 1. Person Singular.