I just finished reading this paper, which describes the situations in which Japanese allows a dative subject and a nominative object. For example, the verb 分かる can be used like this:
"彼" is the subject but is marked with "に" instead of "が", and similarly "英語", the object, is marked irregularly with the nominative particle "が" instead of the usual "を". According to the paper, this happens in Japanese when a verb 1) licenses this case marking and 2) the verb is transitive (there is an object). There are two parts to my questions:
1)The 可能形 licences dative subjects:
This is still ruled out for intransitives, so 5a in the paper shows that you cannot say 「*赤ちゃんにもう歩ける」. Does this change if we add another argument such as a location? Can I say 「人間にはその道が歩けない」 (let's say it's covered in lava or something).
2) The paper also mentions that there are exceptions to this rule, one of them being certain kinds of questions. Can anyone think of a Japanese question with a transitive verb or a verb that doesn't normally allow a dative subject, but which has a dative subject anyway?