Tony,

I'm not certain if I grasp the English description about the rules, but at least I can say it's not so easy to say if the sentences are rude or not.

あなたは車を買いたいですか。
あなたは車を買いたいですね。

Above expressions can be rude depending on the situation, and that means that they are normal expressions at the same time. As you know, our expression can be rude or polite by the person whom you're speaking. So, it's difficult to think a sentence or expression without thinking of the context or situation. The second one might give a little unpleasant impression, but the first one is used commonly.

あなたは車を買いたいと思いますか。

If your textbook says this is more polite, I might be able to say that it's because "と思います" has a fanction of softening an expression. But also this expression can be rude depending on the situation. But there is a definite polite expression here:

あなたは、車のご購入をお考えでしょうか。

It means that I answered properly??

Shizu

Shizu-san, konnichi wa.

I'm sorry, but I still haven't made the question clear.

Our textbooks say nothing directly about the sentence "あなたは車を買いたいと思いますか," which is why we are unsure about why it is acceptable. Zoli (zone-san) saw this as part of a test (テスト).

Our textbooks say:

(1) (私は)水を飲みたい(んです)。
This is OK because 飲みたい refers to 私.
(2) 彼は水を飲みたい(んです)(か)。
This is wrong because one should not say 飲みたい about someone else; one should say 飲みたがる　instead.
(3) あなたは水を飲みたい(んです)か。
This is wrong because it is impolite to ask someone so directly about his or her preference; one should say 飲みませんか instead.

So if we accept that (2) and (3) are not proper, we want to understand why "あなたは車を買いたいと思いますか" is proper (we assume that it must be proper, or it would not have appeared on the test).

I will ask in Japanese later, but I don't have time now-- have to get ready for tea.

--Tony

Tony san, ohayou.

But my answer is the same as the previous one after all. At least the third one isn't okay. I suspect the author doesn't understand Japanese perfectly.

> (3) あなたは水を飲みたい(んです)か。
> This is wrong because it is impolite to ask someone so
> directly about his or her preference; one should say
> 飲みませんか instead.

あなたは水を飲みたい。
This is wrong because we think that it's impossible for us to know someone's wish or desire in his/her mind. We only imagine that, so the sentence should be:
あなたは水を飲みたがっていますね。
You want to drink water, right?

あなたは水を飲みたいですか。
This is okay because this is a question. We are not supposed to be know other's mind actually, so it's quite natural to ask the person to confirm it. It's true, it's really, indeed, definitely okay! As you told me before, some dictionaries and textbooks are not perfect, Tony.

Have a good tea-time!
Shizu

QUOTE:

This is okay because this is a question. We are not supposed to be know other's mind actually, so it's quite natural to ask the person to confirm it.

This is the answer that we were looking for. We suspected that this was the reason, but we needed confirmation. Thank you for your patience.

--Tony