52499
I recently started to learn japanese, and I'm having trouble to distinguish
some of it's phrase structures. I learned that だ is often used in informal
situations representing the です form and か is used to represent a question.

What I really like to know is if the なんだこれ can be used as an answer for
これわなんだか. For example:

これわなんだか - What is this?  
I don`t know, なんだこれわ.

I'm sorry if it sounds a noobie question, but I get a hard time figuring out
how it's structures, because there isn't always a pattern, for instance, I
know about SOV fundamentals, I just don't get the other possible combinations.
CC BY-SA 3.0
2017-08-19T14:38:04.763
52496
2017-08-19T15:16:28.080
25472
question
grammar meaning
これわなんだか and なんだこれ?
First, わ is written as は in your context because the は（wa) is the
subject/topic indicating particle.

これはなんだか cannot mean "what is this?"

"What is this?" should be これはなんですか。or これはなんだろうか。

これはなにか。is also grammatically correct, meaning "what is this?" But it's too
impolite, offensive and demanding. So we usually don't use it in our daily
life.

これはなんだか means something completely different: "Oops! This seems rather..."

なんだこれ＝なんだこれは＝これはなんだ＝"What is this?" In some contexts, it means, "I don't know
what this is."
CC BY-SA 3.0
2017-08-19T15:16:28.080
52499
2017-08-19T15:16:28.080
52496
answer