First post on the forum, quite the lurker. I am currently working through みんなの日本語1and I came about a use of ない that I cannot seem to find an explanation for.
In the instance below I am unsure on why they used the ない form of the verb.
あしたみんなで京都へ行かない?
This chapter is the first one dealing with plain form of speech and I was wondering if that has to do with it, but it does not explain why. Unless I missed something.
This seems to be an instance of using the negative to extend an invitation. So the translation would end up being something like “Do you want to go to Tokyo with everyone tomorrow?”
So if I understand correctly. Because ない form is the plain form and if you want to invite someone to do something you would use ませんか then it would be ない and the か would be dropped since it’s plain form. Resulting in the ない form of the verb.
Leebo already answer this but just to add more info:
In the previous section, we talked about how a question in the plain form usually does not take か, because it can sound overly direct, and potentially rude. Particle か: A Marker of the Unknown