"whose"

[David L. White]

> Isn't cuius cognate to English <whose>?

        I suppose I was not entirely clear about two things.
        First, how Germanic /hwes/ changes into modern English /huz/.
Basically, it doesn't:  the modern form is a reformation from /hu/.  As for
how /hwaa/ changes into /hu/, when it should be /ho/ (as /taa/ gives /to/),
I'm not sure, but I would guess it is infuence of the lost /w/.
In any event, the two /u/s in Latin are from 1) the labio element in a
labio-velar, and 2) raising of /o/, whereas the /u/ in modern English is
mostly from progressive back-rounding of original /aa/, so the similarity is
only a coincidence in the end.
        Second, the IE relevance:  the same sort of process in reverse may
lie behind nominatives in /-(o)s/.  I am not sure whether this is the
Conventional Wisdom these days or not, though it has always seemed good to
me.

Dr. David L. White