re interrogative verbs + interrogative relators + indefiniteordinals

[Matthew S Dryer]

Regarding David Gil's conjecture

(4) Conjecture: question words can "ask about" items belonging to major
(or open) syntactic categories, but not minor (or closed) ones.

I can anticipate various responses to the following, but arguably "which"
is English is an exception, since it is a determiner, a closed class.
Note that one must not confuse an interrogative meaning "which" from one
meaning "what sort of", which English lacks a single word for.  I suspect
that there are languages in which there is a word meaning "what sort of"
that belongs to a closed class of adjectives, but I know of no example.

Also, in many languages, numerals are arguably a closed class, but I
believe that many such languages have a word for "how many".

Matthew Dryer