u/Glum_Entertainment93

Hello! I'm working out my interrogative pronouns, (who, what, where...) and in researching proto-slavic & proto-baltic interrogatives for inspiration, I came across the idea that there is a base interrogative pronoun "ka(s)" in proto-baltic that changes meaning based on what case it declines by (?). How did this system come about? Something confuses me in how the application of cases could change what kind of interrogative the word becomes. Would it decline in the same way that person pronouns do? This is also a phenomenon that I see in a lot of proto-slavic/russian wiktionary entries, and it confuses me really bad so I try not to touch it, lmao!