After I added in-situ (QUE-empty) wh-words to my Russian grammar which simply go through regular head-subject and head-complement (rather than head-filler) rules, I have two new problems:
(1) no question semantics for the phrases built with such words;
(2) sentences like Who sleeps? get two parses, one using the extracted wh-word and a filler-head rule, and another using an in-situ word and the subj-head rule.
Does it sound like I need a new nonlocal feature, similar to QUE? Perhaps QUE can keep indicating that something needs to be extracted, while the new feature would indicate that something is a question but not an extracted one?
I also think that, unless we decide, somehow, that we do not want question-only semantics for in-situ words, then I need more subtypes of interrogative-clause, specifically for the in-situ phrases.
Does it sound like I am on the right track?
Apart from a separate feature which I currently assume I need for proper question semantics in in-situ questions, this would all also be in line with Ginzburg&Sag (2001). It is hard for me to compare our approach to semantics to theirs but I think their analysis works because there, some semantic things are being retrieved or kept in the ``quantifier storage’’, and I don’t understand at this point what makes them either be retrieved or stay in the storage, but that I think is how they avoid ambiguity with in-situ wh-phrases. Regular head-subject and head-complement rules are used up until the very top, but then the sentence cannot become root because there is something yet in the quantifier storage which still has to be retrieved. The in-situ-interrogative-clause rule does that, and then we have a sentence. Something like that.
We don’t have a quantifier store, so it sounds like we’d be using some additional SLASH-like mechanism here, except we wouldn’t be using it in head-filler rules but would have an unary rule which adds question semantics to something that has a non-empty list of this kind and makes the list empty, after which the sentence can fire?