どうして田中が好きなんですか
From what i understand, the sentence above doesn't have any subject, so depending on the context, it can be both Why do I like Tanaka? or Why do you like Tanaka?
Is this correct ?
どうして田中が好きなんですか
From what i understand, the sentence above doesn't have any subject, so depending on the context, it can be both Why do I like Tanaka? or Why do you like Tanaka?
Is this correct ?
(As l'électeur pointed out, the grammatical subject of 田中が好き is 田中 (here's why). But I'm assuming you're concerned about the person who likes 田中.)
どうして田中が好きなんですか can mean "Why do you like Tanaka" (second person) or "Why does he/she like Tanaka" (third person), depending on the context.
But it almost never means "Why do I like Tanaka?" (i.e., "I know I like Tanaka, but I wonder why I like him.")
If "I" (as the first person) don't know why "I" like Tanaka, "I" have to say:
- どうして田中が好きなんだろう?
- どうして田中が好きなんだろうか?
Here, this だろう is an "I-think / I-wonder" marker (I don't know how to call this properly).
~ですか? can be used only when the speaker explicitly requests the answer, believing the listener knows the answer. Saying どうして田中が好きなんですか to yourself is almost like saying "Tell me why do I like Tanaka!" to yourself!
Likewise, どこに行くんですか? can mean "Where will you/we/he/she/they go?", but it never means "Where will I go?". When you want to ask yourself such a thing, you have to say "どこに行こう?" using the volitional marker う/よう.
In this case, it can be any one else, but not yourself.
Making a question sentence whose subject is the first person is highly restricted, because ordinary Japanese question expects the speaker doesn't have firsthand knowledge about what's asked. It'd thus sound very, very weird if you ask something about yourself that you ought to feel or know inside you. To avoid this, you can add だろう (or polite form でしょう) to show the existence of introspection.
どうして田中が好きなの?
Why [ × do I / do you / does somebody ] like Tanaka?(cf. どうして田中が好きなのか Why [ I / you / somebody ] like(s) Tanaka )
(casual plain form + か can't form a valid wh-question, but only indirect question, unless in the construction~は + wh + か
)どうして田中が好きなんだろう(か)?
Why [ do I / do you / does sb. ] like Tanaka (, I wonder)?どうして田中が好きなんです(か)?
Why [ × do I / do you / does sb. ] like Tanaka? (polite)どうして田中が好きなんでしょう(か)?
Why [ do I / do you / does sb. ] like Tanaka (, I wonder)? (polite)
Maybe you've heard the questioner in TV quiz program sets problems to the panel using でしょう ending. It's a good example that suggests the questioner is asking them knowing the answer.
Of course, in following cases you can dispense with だろう:
どうして田中なんか好きになっちゃったの? Why (at all) did I fall in love with a guy like Tanaka?
(what is beyond your control or expectation)どうしたら健康で長生きできるのですか? How can I live a long, healthy life?
(what is out of your knowledge)ここはどこですか?私は誰ですか? Where am I? Who am I?
(...or you've lost it)