Commands in the negative

[AlwaysLost]

I am reading that for irregular verbs...
Salir -> sal
Hacer -> haz
Poner -> pon

The next part is confusing. The example given states that pon -> No pongas. But in class my notes state sal -> No sal, and hazlo -> No lo hagas. Why isn't sal -> no salgo?

[poli]

It should be no salgas

[Glen]

A grammarian can put it better than I can, but what I recall hearing is that Spanish uses the more formal construction for negative commands so as to show respect for the person being commanded not to do something. Native speakers, correct me if I'm way off base!

[AngelicaDeAlquezar]

I am reading that for irregular verbs...
Salir -> sal
Hacer -> haz
Poner -> pon

The next part is confusing. The example given states that pon -> No pongas. But in class my notes state sal -> No sal :bad: (This is wrong), and hazlo (This is only when you know what the activity you're not supposed to do is. "Lo" is the direct object pronoun that replaces that activity in the order) -> No lo (Same as previous; this pronoun is not a part of the conjugation) hagas. Why isn't sal -> no salgo (This is the present indicative for the first person (yo); this doesn't belong in the imperative form)?



For both regular and irregular verbs, the negative form needs the subjunctive for all persons, but the subjunctive is not used for "tú" or "vosotros" in the "positive" imperative conjugation.

Salir
sal (tú)
salga (usted)
salid (vosotros)
salgan (ustedes)
*salgamos (nosotros) -> Not all grammarians agree that "nosotros" should be included in the imperative mood, but I agree with the ones who do.

no salgas (tú)
no salga (usted)
no salgáis (vosotros)
no salgan (ustedes)
*no salgamos (nosotros)


Hacer
haz (tú)
haga (usted)
haced (vosotros)
hagan (ustedes)
*hagamos (nosotros)

no hagas (tú)
no haga (usted)
no hagáis (vosotros)
no hagan (ustedes)
*no hagamos (nosotros)


Poner
pon (tú)
ponga (usted)
poned (vosotros)
pongan (ustedes)
*pongamos (nosotros)

no pongas (tú)
no ponga (usted)
no pongáis (vosotros)
no pongan (ustedes)
*no pongamos (nosotros)


I think what your lesson is about is that these verbs don't use the "-ga" fragment when conjugated in the imperative for the second person ("tú" / "vosotros"), unless it's the negative form. :)