が vs を and the absence of a subject particle

Question

I just read an article explaining that が should not be thought of as a subject particle, since it can also mark the object, which is fine and dandy on its own.

However, I also remember reading an article that explained that when certain transitive verbs (e.g. 話す) get conjugated into particular forms (e.g. potential), anything that would have been marked with を is instead marked with が.

At first, these two bits of information seemed contradictory (the fact that the latter was explained in terms of the object becoming the subject didn't help). In trying to reconcile them, however, I came to the conclusion that を can be replaced with が (with a change in nuance), but が can't (necessarily) be replaced with を. Does this seem accurate, or is one of the sources of information wrong?

Answer 1

From the article:

クレープが食べたいから。

The subject of this sentence is crepe. 食べたい does not mean "wants to eat" any more than 好き means "likes". 食べたい functions as an adjective, expressing that crepes are "eatable" (not in an ability way, but in a preference way). It's no coincidence that 〜たい constructions conjugate exactly like い-adjectives.

So, literally: "Because crepes are eatable."

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It's conspicuous that Mr. Kim didn't provide any other examples of が marking an object. To play devil's advocate though, I'll come up with one on his behalf:

私は日本語が分かります。

The most natural way to translate this into English is "I understand Japanese."

"I" is the subject, "Japanese" is the object. Simple.

Unfortunately (or fortunately, depending on your point of view) English is not Japanese.

What's going on in the Japanese is more like this: "As for me, Japanese is understandable."

This is because 分かる is an intransitive verb. It doesn't take an object like "understand" does in English. In Japanese, something "is understandable," or "is clear." All you have to do to verify this is look up 分かる in the dictionary of your choice.

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So I would take what Tae Kim says with a grain of salt. Calling が the subject marker is totally kosher.

(Calling は the subject marker, on the other hand......)

Answer 2

I think が functions as both a subject marker and a kind of object one, not solely subject.

What Tae Kim calls identifier actually can be explained as emphatic construction. For example, when you rephrase 食べたのは魚だ (it's fish that I ate), you say 魚を食べた (often with stress on を), not 魚が. So, it's not so much function of が itself as the case particle not being topicalized because of emphatic construction.

Next, the reason why could-be objects for potential verbs or the likes are not a subject can be understood from comparison between these examples.

• 俺が怖い？
• ワタシ、キレイ？

Given that both of them are question with Sentence of neutral description, thus, the subject is indicated with Zero particle in the latter sentence (the famous question by Kuchisake-onna). However, the first one still has が because it means "Do you find me scary". If it meant "Am I scary?", it would be "俺、怖い？". This shows how aforementioned が is different from the general subject marker one, apart from if you regard it as an object or another subject.