I really hate the idea of saying corrected in this context. There is really no right and wrong in language iself. Standardized language is not some “correct” way to speak, but a common guide to try to help an individual be understood by more people. Someone not following standard is not wrong, just maybe difficult to comprehend due to not following convention. I think in one off mistakes that are hard to understand, it is better to thinking in terms of asking for clarification. In more consistent problems of understanding, I think explaining (which is not the same as correcting) to them a more conventional way of speaking to easy future communication is the best path.
Also equating individuals unique linguistic quirks to cancer is gross.
Be mad then I guess lol