For instance. I was wondering whether “私が弟がいる” or something similar could occur opposed to “私に弟がいる”, not so much with these concrete nouns but simply whether “いる” when used like this must take a dative subject by necessity, or can also take a nominative one. One can use google for this by filling in the nouns and hoping for a match but it would be nice to have a tool where one can enter something such as `\NPが.*\NPが(居|い|有|あ)る` with the system smart enough to return any noun phrase at the place of `\NP` so that I can see whether this structure actually occurs.
At the very least, a tool that can search in them simply by regular expressions alone would be nice.
2 comments
https://massif.la/ja may be what you’re looking for?
Google already supports `*, AND, OR` operators. Something like:
`“私が * がいる”`
or
`“私が 妹|弟 がいる”`
This seems like a bad way to learn something like 居|い|有|あ, though.