When to use ぬ form?

[KyleGoetz]

最初の投稿者：Sashimister

「そんなこと分からないよ！あすかちゃんも分からない でしょう。」 sounds pretty natural. To make it sound even more, I'd say でしょ instead of でしょう. That would go with よ better.

I don't think too many native speakers would consider your second sentence as being "polite", though. With ちゃん and 分かる, it sounds fairly informal to me. Had you said something like あすかさんもお分かりにならないでしょう。or あすかさんもご存じないでしょう。, then I would have called it polite (and you would have sounded weird ).

I always seem to have trouble discussing plain/polite/informal/formal with Japanese learners. (This means I have trouble almost every day!) I'm the kind to go facepalm everytime someone tries tell me です/ます is polite or formal because that's considered so boringly average here in Japan.

It's like even though my family have been speaking Japanese for 2,000 years but I sometimes have a first-year Japanese learner tell me what to do with my Japanese. Not talking about you, KyleGoetz, though.

I completely understand that ます is average. It's just that darn terminology. To draw a contrast with the dictionary/plain form (I realize "dictionary" is just "plain non-past" technically), we call ます form "polite." I guess we could call it "non-plain"

So I didn't mean to imply with ちゃん and such it is actually polite per se. What I was just concerned about was ending the first sentence with ない and the second with でしょ（う） instead of だろう. It's just that, in my head, ない and だろう are "plain" form, so they need to be used together when talking to the same person. I didn't know you could mix and match plain and ます form when talking to the same person!

Thanks for the lesson!

[Sashimister]

最初の投稿者：KyleGoetz

I completely understand that ます is average. It's just that darn terminology. To draw a contrast with the dictionary/plain form (I realize "dictionary" is just "plain non-past" technically), we call ます form "polite." I guess we could call it "non-plain"

So I didn't mean to imply with ちゃん and such it is actually polite per se. What I was just concerned about was ending the first sentence with ない and the second with でしょ（う） instead of だろう. It's just that, in my head, ない and だろう are "plain" form, so they need to be used together when talking to the same person. I didn't know you could mix and match plain and ます form when talking to the same person!

Thanks for the lesson!

You could use だろう in the second sentence, provided that a particle like な, ね or　なあ is attached to it. Without the little ender, it would sound lifeless (textbook-like).　

Sentence endings are very important in our language.　These little particles are so pregnant with meaning.

[chryuop]

最初の投稿者：Sashimister

「そんなこと分からないよ！あすかちゃんも分からない でしょう。」 sounds pretty natural. To make it sound even more, I'd say でしょ instead of でしょう. That would go with よ better.

I don't think too many native speakers would consider your second sentence as being "polite", though. With ちゃん and 分かる, it sounds fairly informal to me. Had you said something like あすかさんもお分かりにならないでしょう。or あすかさんもご存じないでしょう。, then I would have called it polite (and you would have sounded weird ).

I always seem to have trouble discussing plain/polite/informal/formal with Japanese learners. (This means I have trouble almost every day!) I'm the kind to go facepalm everytime someone tries tell me です/ます is polite or formal because that's considered so boringly average here in Japan.

It's like even though my family have been speaking Japanese for 2,000 years but I sometimes have a first-year Japanese learner tell me what to do with my Japanese. Not talking about you, KyleGoetz, though.

I know what you mean. For us learner the level of politeness is by far the hardest thing to understand. For example it pretty much shocked me seeing that from a colloquial form to go to a polite form you used streight honorific.
I guess the levels of politeness is a thing strictly attached to your culture and simply studying few grammar rules don't even get us close to understanding.