Waaay off topic, but does anyone know why LLMs don't have poor grammar if they were trained on the average/poor grammar of the internet? Why don't they mix up then/than or it's/its, or use hypercorrections like "from you and I"?

(Update: of course I had to ask my friendly neighborhood LLM, and the answer is the correct usages still dominate incorrect ones, so statistics favor correctness. They down-weight low quality sources (comments like mine) and up-weight high quality ones (published books, reputable news sites). Then human reinforcement learning adds further polish.)