>>18058914
Did you know that both interrogatives and demonstratives are in correspondence?

For those who would say these similarities are due to mere language contact, please explain:
why is it that the similarities are already present at the level of PU and PIE before the breakup of either language into descendant languages?
what exactly do you have in mind for language contact? PU was becoming so mixed up with PIE linguistic features that it was well on its way to becoming a pidgin to enable a degree of mutual intelligibility?
how does that work if they are supposedly 5000 km apart?