Grammar: about "o" and "ga" for direct object

[patroclus]

私 は りんご が 食べたい です

would this means "about me, I wan't to eat an apple (but the apple is not there)" ?
I know I can use "o" particle, but I as read in a grammar book, "o" is used if the apple is in front of you, for example, weather "ga" is used if no object is phisicaly there... right?

Imagine I want to be the subject, that is "私 が". how could I use が for りんご too?

 

[The7thSamurai]

'Ga' answers the question of 'what', 'when', 'where' etc.

Nani ga tabetai desu ka? (What do you want to eat?)
Ring ga tabetai desu. (I want to eat an apple.)

I'd say the reason your text book explained it in that way (the in front/not in front way) is probably because when someone asks you what you want to eat usually the food isn't in front of you. However, if there was no question involved, and you simply stated the fact that you want to eat an apple, then I guess you could use 'o'. Maybe you walk into a room and see an apple on the table and think to youself "hmm, I'd like to eat that apply", i.e., no one asked you a question, therefore 'ringo o tabetai'.

 

[The7thSamurai]

Oh, and to answer your question about using 'watashi ga', think about what I said previously about the 'ga' marker. It answers a question. So if someone said 'watashi ga ringo o tabetai', obviously the question before it would have been 'dare ga ringo o tabetai' (or, 'who wants to eat the apple?'). You would therefore use 'o' to mark 'ringo' because that part of the sentence doesn't answer a question.

 

[Glenn]

According to Kuno stative transitive predicates take ga for object marking, so nihongo ga wakaru; eigo ga dekiru; okane ga hoshii; Yasuko ga suki da; kore ga tabetakunai; etc. This ga is different than the ga for subject marking.

Now, there are basically three patterns for marking subjects and objects with these types of predicates, and it's claimed that they all stem from one source: NP-ga NP-ga stative predicate. The variations are NP-ga NP-o pred. and NP-ni NP-ga pred (NP = noun phrase). Each can be used in certain situations but not others. The point is, both watashi ga ringo ga tabetai and watashi ga ringo o tabetai are perfectly good sentences (I'm not sure about watashi ni ringo ga tabetai, though, but my guess is it's not acceptable). As far as what the difference is, Kuno says that with the ga version you're taking the noun phrase to be the object of the derivative as a whole, which are stative by assumption; with the o version, the noun phrase is taken to be the object of only the verb stems, which are action verbs. I'm not sure how much that means to you, but it doesn't really seem to help to much with how to interpret them.

As for the difference in interpretation, it says in "A Dictionary of Basic Japanese Grammar" that the ga version shows a higher level of desire, where the o version shows a lower level. It offers these sentences as examples: [Situation: The speaker has just run five miles] watashi wa mizu ga/?o nomitai. (The ? means the sentence is questionable) [Situation: The speaker has been told by a doctor to drink as much water as possible. That is, he feels he has to drink water] watashi wa mizu o/?ga nomitai ga... (implying that his stomach won't accept any more). I'm not sure how true this is; we'll have to ask some native Japanese speakers how they feel about it or read some more recent works on the issue (ADBJG is copyright 1986 and 1989).

 

[The7thSamurai]

Glenn, how would you ask and answer the question "who wants to eat what?". Imagine you're asking a whole bunch of friends at a dinner table what they want to eat. Can such a sentence be asked?

 

[Elizabeth]

「私は水が食べたい」の場合、ほかの飲み物については言及されて
いるように思えないと思います。「水でなければ満足しない」
という状況が表われますか。

「水を飲みたい」の場合、水のほかの飲み物でもいい」という感じがするかもしれないです。

欲しいもの、希望を強く表現するのに「が」が使われることが多いと思います。

もちろん、以上は私の個人にとしての意見であるだけです。人によって違うでしょうね。

 

[patroclus]

According to Kuno stative transitive predicates take ga for object marking, so nihongo ga wakaru; eigo ga dekiru; okane ga hoshii; Yasuko ga suki da; kore ga tabetakunai; etc. This ga is different than the ga for subject marking.

kore ga tabetakunai ?

Isn't taberu a continual verb (not stative) ?

If it were stative, it would need ga to mak object so

watashi ga ringo o tabetai

what would be "o" here?

 

[Elizabeth]

Glenn, how would you ask and answer the question "who wants to eat what?". Imagine you're asking a whole bunch of friends at a dinner table what they want to eat. Can such a sentence be asked?

Sorry for not being Glenn....he may have a different idea but I seem to recall this as acceptable :

Dare ga nani wo tabetai no ka oshiete kudasai.

 

[Glenn]

「私は水が食べたい」の場合、ほかの飲み物については言及されて
いるように思えないと思います。「水でなければ満足しない」
という状況が表われますか。

「水を飲みたい」の場合、水のほかの飲み物でもいい」という感じがするかもしれないです。

欲しいもの、希望を強く表現するのに「が」が使われることが多いと思います。

もちろん、以上は私の個人にとしての意見であるだけです。人によって違うでしょうね。

Your impressions are pretty close (if not exactly the same) to what Makino and Tsutsui have claimed.

 

[Glenn]

Glenn, how would you ask and answer the question "who wants to eat what?". Imagine you're asking a whole bunch of friends at a dinner table what they want to eat. Can such a sentence be asked?

I would say that either dare ga nani ga tabetai desu ka or dare ga nani o tabetai desu ka would be acceptable, depending on how badly you think the people want to eat.

[Edit] And after looking at Elizabeth's response, also depending on the "Japaneseness" of the sentences. What I mean is it depends on whether a Japanese person would ask the question in a straightforward manner like that.

 

[Glenn]

Isn't taberu a continual verb (not stative) ?
If it were stative, it would need ga to mak object so
what would be "o" here?

Taberu is an activity or accomplishment verb (or continual, but I'm not really used to that terminology), but it's derivative form tabetai is stative, i.e. it shows the state of wanting to eat. Therefore, it takes ga as an object marker. But, it can also take o, as has been said before. O is the object marker there. It basically boils down to the -tai form being able to mark objects with either ga or o, depending on the degree of desire to perform some activity on something.

 

[Elizabeth]

Glenn, how would you ask and answer the question "who wants to eat what?". Imagine you're asking a whole bunch of friends at a dinner table what they want to eat. Can such a sentence be asked?

Of course a direct translation is quite understandable
誰がどの食べ物を欲しいんですか？」「誰がどれを食べたいのですか]
誰がどの食べ物なのを（か？）教えてください。

but the friend I asked about this suggested these instead.
それぞれ注文したものを教えてください。」 (a restaurant situation)
とか「各自、自分の食べたいを取ってください。:hungry: