"Do not come here."
Translation:Non venire qui.
Why is this in infinitive form, and not: Non vieni qui? I do not understand the differerence.
The infinitive is used to cover the second person singular of the negative imperative; "non vieni qui" means you're not coming here (simple present).
Hmm.. Is there a second person alternative besides imperative? The imperative is not only for second person singular, it's just for any person and any number, isn't it?
Not for any person and number, as you can't order yourself, so the first person is always missing; in Italian it's fused with the exhortative (taken from subjunctive) so it has an almost complete conjugation. I'm not sure what alternative you're looking for, the English "do not come here" is certainly imperative, so it's either "non venire qui" or "non venga qui" (formal you).
That's right, the English could be plural too. The plural of the formal you is Loro, so it would be "non vengano qui", but while Lei became so popular that it even took the polite voi's place, Loro is felt as very polite and formal, so people often switch to the normal voi when addressing more than one person (non venite qui).
The negative imperative for tu (second person singular) in all conjugations is formed by placing non before the infinitive. The noi (though rarely used) and voi forms are identical to those in the affirmative.
From what I have read, Qui means: precisely right here. While Qua means: here in this general area. The same seems to go with the Italian words for "There". Lì means: precisely right there. While Là means: there in that general area. Hope this helps!
Why is "He does not come here" acceptable? How would you say that in Italian if "Non venire qui" means "Don't come here?"
Since "does not come" is in the present tense, you would conjugate the infinitive «venire» to the present «lui (non) viene», just like in English you would conjugate the infinitive "to come" to the present "he comes" (or, in this case, "he does not come"). Therefore, in Italian, "He does not come here," would be "«(Lui) non viene qui.».
«Non venire qui.» is the imperative "Do not come here," for an informal "you," e.g. if you were telling your sibling or classmate not to come here. «Non venga qui.» is the imperative "Do not come here," for a formal "you," e.g. what you would use for a teacher, a boss, or anyone that is higher in you in rank or age that you would use the «Lei» form.