Okay, that's weird. Where is my Spanish coursebook?
Anyways...
To translate "don't ask" and "don't talk", we have to use the imperative form "no pregunta" et "no habla", and not the subjonctive present tense "no preguntes" and "no hables". That would be wrong to say it that way.
I can't find my coursebook, so as to double-check, but I'm pretty certain I was taught that, when used in negation, the imperative form changes and coincides with subjunctive present.
This site agrees with me.
Ann - thank you for the compliments

Truth is, I enjoy learning foreign languages, and my teachers have said I'm talented at it. It's practice that makes perfect, though - and hanging around the boards, reading and writing fic, is the best practice one can hope for
Also, I don't know how much it counts coming from a non-native English speaker, but I think your English is excellent

If you hadn't said it yourself, I still wouldn't have realized you're not a native English speaker, either.
See ya,
AnnaBtG.