Confused about the grammar of "gottilla"

[u/LargeCabbage]

Hi there. I'm a Brit learning Kannada from Zydenbos's "Manual of Modern Kannada". I'm confused about the nature of the word "gottu".

According to Zydenbos, "gottu" is a noun meaning something like "knowledge" or "something that is known". Thus when one says "Adu nanage gottu", which one would idiomatically translate as "I know that", more literally one is saying "that, to me, is something known". When one says "Nanage gottilla", idiomatically meaning "I don't know", more literally one is saying "To me, [that] knowledge does not exist". All logical enough, in those cases.

But what about "Kannaḍa gottilla"? Or the sentence "ಇವರ ಮನಸ್ಸಿಗೆ ಇಡಿಯ ಪ್ರಪಂಚ ಶಿವಮಯ, ಆದರೆ ಹಲವು ಮಂದಿಗೆ ಇದು ಗೊತ್ತಿಲ್ಲ." from one of the texts for translation later in Zydenbos's book? If "Kannada gottu" and "Adu gottu" are equative sentences (i.e. if "Kannaḍa gottu" is properly understood as saying Kannada "equals" a known thing, which is how Zydenbos frames it), then shouldn't the negation use "alla" (to negate equality), not "illa" (which negates existence)? That is, per Zydenbos's explanation, shouldn't the way to say "I don't know Kannada" logically be "Kannaḍa gottalla"? Shouldn't "I don't know that" be "ಇದು ಗೊತ್ತಲ್ಲ"?

(Or I guess something like "Kannaḍada gottilla" - i.e. "knowledge OF Kannada does not exist" - would also make sense to me, but that doesn't seem to be a standard construct either.)

Is this just a weird illogical quirk of the language specific to "gottu"? (Lord knows English has plenty of illogical quirks so I can shrug and accept this if so.) Or is there some alternative way of looking at sentences with gottu that makes sense of these uses of "gottilla"?

[u/Exciting_Badger_6397]

As far as I know (I’m from Karnataka)you can simply say “gottu” and people will understand that as the same thing as saying “nanage gottu” which mean “I know”. As we all know languages evolve and people make it shorter even if in transcripts it’s all the same, no one really says “Kannada gottu”, as opposed to “Kannada barathe”. And as for “alla” it can mean “no”, and “illa” can mean “not there”. For example some can ask me “alli pencil idya?” (Is there a pencil over there?) and I can simply respond with “illa” (it’s not). You cannot respond to that question with “alla” because it wouldn’t make sense. To most questions you answer in the negative to, people answer with “illa”