# koto ga dekiru vs. the potential form in verbs



## Sulizhen

Hello,

I have a question related to these two forms of expressing the ability to do something. Usually, I use them as "synonim" forms. But what I want to know is if they are really "interchangeable" or if there is any difference between them, no matter how slight this difference is.

I've read somewhere that "...(koto) ga dekiru" is a little bit more formal than the verb in potential form, but I don't know if this is true...

Thanks in advance


----------



## toscairn

> (koto) ga dekiru" is a little bit more formal than the verb in potential form, but I don't know if this is true...


Yes, "koto ga dekiru" has a more formal ring to it, than saying for example, "oyogeru."


----------



## Sulizhen

Kamome, toscairn, thank you for your replies 

 Then, _dekiru_ is more formal than the potential form of the verb. I must suppose that it is preferred in written language, ne?



			
				moodywop said:
			
		

> _I've often been taught that DEKIRU is mostly suitable to express a real/physical chance/skill to do something, as for instance:_
> 
> _OYOGU KOTO GA DEKIMASEN / DEKINAI (I CAN'T SWIM)_
> 
> _...but I need to say that I consider myself nothing more than a bad student..._
> 
> _kamome_



Hmmm... I see... And is that usual? I mean... Is this a "rule" that is applied in "real" (formal) Japanese? (I ask this just by curiosity, please don't think that I distrust your kind explanation...).

Now, if you don't mind, I would like to take advantage of your kindness and ask you something else about the potential form/_dekiru_ matter:

Verbs in potential form work as intransitive verbs, so they mark the direct object with "ga" instead "wo" (_watashi wa baiorin ga hikemasen_). In the grammar I have, however, it's said that if there is any chance of confusing this object with the subject (e.g. when the object is a person, but it's not the subject of the sentence), then you can use "wo" to mark the object. They put these two sentences as example:

(excuse for not writing with _kanas _but I have to reinstall some of the Windows features)
_
Tanaka-san wo tetsudaeru hito ga imasuka._ (Is there someone who can help Tanaka?)
_Tanaka-san ga tesudaeru hito ga imasuka. _(Is there someone who can be helped by Tanaka?)

What I want to know is... Is this really a usual case in Japanese or this just happens once or twice in a million of sentences?

In other of the grammars I have it's said that in case of _koto ga dekinai/dekimasen_, _ga_ is commonly replaced by _wa_, while the affirmative form uses _ga_. Is that true?

I hope to not bother you with my questions... Thanks again!!


----------



## toscairn

> Then, dekiru is more formal than the potential form of the verb. I must suppose that it is preferred in written language, ne?


To be more precice, "koto ga dekiru" is more formal (so, better be avoided in conversations). "dekiru" itself is not. 

e.g. shigoto ga dekiru. 仕事ができる。(I can [am able to] work.)unntenn ga dekiru 運転ができる。(I can [am able to]drive.) 

These sentences are quite as natural in conversations as in formal writings.　The phrasing "(NOUN) ga dekiru" works in any situation.
However, the phrasing "(VERB) koto ga dekiru" or "(NOUN) suru koto ga dekiru" is pretty much "formal." Better be avoided in conversations, and inflex the verb instead. It's quite parallel to this: you say "you *may *choose this computer" rather than "you *are allowed to *use this computer." Why bother saying "are allowed to" when there is a useful and appropriate word "may"?  Likewise, why bother saying "oyogu koto ga dekiru （泳ぐことができる）" when there is a more convenient word (and just one word!) "oyogeru（泳げる）"?

It is not "dekiru" itself, but "koto" that makes it sound formal. 

e.g. 入るのは簡単だが出るのは大変だ。(hairu no wa kanntann daga deru no wa taihenn da) It's easier to enter than to come out of it.

This becomes more formal by replacing "no" with "koto," for example,

入ることは簡単だが出ることは大変だ。


----------



## toscairn

As for Kamome-san's explanation, it's hazure (はずれ). Better luck next time!

But he brought up this interesting topic: Does Japanese have verbs equivalent to "potere/poder" and "sapere/saber"? The answer is NO. "dekiru" covers both of these Italian/Spanish verbs. How do you distinguish both usages? You check adverbs or adverbial phrases, just as you recognize a sentence as future tense by doing the same thing. You know, Japanese has no future tense: we attach modifiers to determine the tense.

e.g. 今日プールで泳げます。kyou puru de oyogemasu. Today I can/am able to swim in the pool.

This sentence can both mean "I'm can swim today because I feel good today." (physical readiness) and "I get to swim in the pool because it is open today." Its context or the adverb like "kyou" is the determiner (whether it's "poder" or "saber." )

e.g. 今日市民プールは開いているから泳げます。kyou shiminn puru wa aiteiru kara oyogemasu. "The City Pool is open today, so I can swim."

This sentence doesn't mention the speaker's ability to swim, nor is it about the speaker's readiness to swim; but the pool's availability. It's context and/or modifiers that determine if it's about ability or availatility.


----------



## toscairn

Verbs in potential form work as intransitive verbs, so they mark the direct object with "ga" instead "wo" (watashi wa baiorin ga hikemasen). In the grammar I have, however, it's said that if there is any chance of confusing this object with the subject (e.g. when the object is a person, but it's not the subject of the sentence), then you can use "wo" to mark the object. They put these two sentences as example:

(1) Tanaka-san wo tetsudaeru hito ga imasuka. (Is there someone who can help Tanaka?)
(2) Tanaka-san ga tesudaeru hito ga imasuka. (Is there someone who can be helped by Tanaka?)

What I want to know is... Is this really a usual case in Japanese or this just happens once or twice in a million of sentences?

One correction: the sentence (2) can mean either (1) or (2). That's why the use of "ga" as employed in (2) is so confusing! Fortunately, many Japanese have begun, I believe, to acknowledge the particle's ambiguity, and make sure to use "wo" as many times as humanly possible (others may disagree, though).

Having said that, some types of verbs can't be accompanied by "wo." 

e.g. あなたが好きだ。anata ga suki da (I like you.)
*あなたを好きだ。　anata wo suki da 

The one with the asterisk is not possible, you should use "ga" in that sentence. I hazard a guess. 形容動詞 (keiyou doushi)　can't coexist with the particle "wo."


----------



## toscairn

> In other of the grammars I have it's said that in case of koto ga dekinai/dekimasen, ga is commonly replaced by wa, while the affirmative form uses ga. Is that true?



I'd say, no, it's not true. You should follow the definition of the particles "ga/wa" in your grammar book and stick with it here.

e.g. 彼は泳ぐことができない。(kare wa oyogu koto ga dekinai) 

Above is a general statement. "He isn't able to swim."

e.g. 彼は泳ぐことはできない。(kare wa oyogu koto wa dekinai)

This kind of sentence usually requires some following-up sentences, like this:

しかし、ボートを持っている。　(shikashi, boto wo motte iru) (but he has a boat.)

"wa dekinai" implies that he is able to do other things instead.

Back to the original, I'm sure that your grammar books are making this point:

Antonio wa chess ga dekinai./Antonio wa chess wo surukoto ga dekinai.(Antonio can't play chess.)
*Antonio ga chess ga dekinai./*Antonio ga chess wo surukoto ga dekinai.

In above examples, the asterisked sentences are not acceptable. That must be what the authors are saying. The asterisked sentences are possible only when those constitute as a subjective entity.

e.g. Antonio ga chess ga dekinai koto wa minnna wo gakkari sasemashita. (That Antonio can't play chess disappointed everybody.)


----------



## Sulizhen

Toscairn-san, thanks a lot for your help!! 

I will take good account of all of your advises and examples. Since I study by myself and with no help from a native teacher, I have a lot of doubts -specially if we bear in mind that some of the explanations and examples in books are related to "ideal" situations and so forth.

Again, thanks for your help. I'm afraid that you'll see me asking something more around here... uh...

Sulizhen


----------



## Sulizhen

toscairn said:
			
		

> e.g. 彼は泳ぐことができない。(kare wa oyogu koto ga dekinai)
> 
> Above is a general statement. "He isn't able to swim."
> 
> e.g. 彼は泳ぐことはできない。(kare wa oyogu koto wa dekinai)
> 
> This kind of sentence usually requires some following-up sentences, like this:
> 
> しかし、ボートを持っている。　(shikashi, boto wo motte iru) (but he has a boat.)
> 
> "wa dekinai" implies that he is able to do other things instead.
> 
> Back to the original, I'm sure that your grammar books are making this point:
> 
> Antonio wa chess ga dekinai./Antonio wa chess wo surukoto ga dekinai.(Antonio can't play chess.)
> *Antonio ga chess ga dekinai./*Antonio ga chess wo surukoto ga dekinai.
> 
> In above examples, the asterisked sentences are not acceptable. That must be what the authors are saying. The asterisked sentences are possible only when those constitute as a subjective entity.
> 
> e.g. Antonio ga chess ga dekinai koto wa minnna wo gakkari sasemashita. (That Antonio can't play chess disappointed everybody.)




 I forgot this when I wrote my message before... I was reading again the book I told you, and the sample sentence is:

_Tsumari, subete no tetsuzuki o sumasanai to, nyuuin suru koto wa dekimasen._

 And the explanation of the authors is that when it comes to negative form, _koto ga dekinai_ is often replaced by _koto wa dekinai_.

 Maybe they wanted to express the same idea as you, but it seems they forgot to say that adding something else, an "explanatory sentence" or something similar, would be required. If it's that the case, then, sincerely talking, I prefer your explanation. It's clear and precise


----------



## Flaminius

Sulizhen,

In your example sentence, the verb nyūin-suru is formed by a noun nyūin (入院; admission to hospital) with a light verb suru.  Noun-derived verbs suffixed with suru cannot form potential forms using -areru/-eru/-reru.  In order to express the idea of something possible, therefore, those verbs resort to "koto-ga/koto-wa dekiru" construction.

"Koto-ga dekiru," to my mind, is a cumbersome device at best.  You may want to use a shorter form, "nyūin dekiru".  The negative form is, "nyūin dekinai."

_Tsumari, subete no tetsuzuki o sumasanai to, nyuuin suru koto wa dekimasen

_I would rewrite the sentence using the shorter form:
つまり、すべての手続きを済ませないと、入院できません。

While there is nothing wrong with "X surukoto-ga dekimasen," I observe that "X dekimasen" is used with similar attitude but with more pulmonic ease.

Flaminius


----------



## Oogami

I was under the impression that 「できる」is the potential form of 「する」 that indicates [able to do].
(That was what I remembered being taught anyway)

Verbs

Group 1 - 泳ぐ >> 泳ぐことができる >> 泳げる
Group 2 - 食べる >> 食べることができる >> 食べられる
Group 3 - する >> することができる >> できる
Group 3 - 来る >> 来ることができる >> 来られる

I really, really need to go back and polish up my basics again.
But learning languages just for the sake of learning is fun (when there is no exam  ). Despite the extra headache inducing layers of formality in the Japanese language.


----------



## Sulizhen

Thanks everybody for all your explanations!! They were really helpful


----------

