About the な part in negative imperative verb form (e.g. 飲むな)


In the Japanese version of "don't drink and drive" slogan, 【乗るなら飲むな】 (also
【飲んだら乗るな】), what part of speech is the な that follows the plain verb 飲む (or 乗る
in the second variation) to form the negative imperative verb form?

At first I thought it was a conjugation, but a conjugation modifies the verb
that it attaches to, whereas 飲む and 乗る are left unmodified before the な. I am
thinking maybe it is a special usage of the な particle, but I don't discount
the possibility that it is entirely a different species.

Also, what of its origin? Did it come from abbreviation of longer clauses like
「飲む無しに(して/しろ)」 etc, or from something else?




It's the strongest, tersest form of negative. It always follows a plain form
verb. I have no idea of the origin; it's pretty old though:)

Regarding the origin, it goes back to at least the 8th century in this form:

活用語の終止形に付いて、「～するな」と禁止する意をあらわす。現代口語に継承されている。

大和道は雲隠れたりしかれども吾が振る袖をなめしと思ふ **な** （万葉集、筑紫娘子） こちふかば匂ひおこせよ梅の花あるじなしとて春を忘る **な**
（拾遺集、菅原道真）

Source: <http://www.asahi-
net.or.jp/~sg2h-ymst/yamatouta/intro/josi05.html#ab17>




It's the strongest, tersest form of negative. It always follows a plain form
verb. I have no idea of the origin; it's pretty old though:)

Regarding the origin, it goes back to at least the 8th century in this form:

活用語の終止形に付いて、「～するな」と禁止する意をあらわす。現代口語に継承されている。

大和道は雲隠れたりしかれども吾が振る袖をなめしと思ふ **な** （万葉集、筑紫娘子） こちふかば匂ひおこせよ梅の花あるじなしとて春を忘る **な**
（拾遺集、菅原道真）

Source: <http://www.asahi-
net.or.jp/~sg2h-ymst/yamatouta/intro/josi05.html#ab17>

