It can’t learn because it isn’t intelligent. It’s a markov chain.
There is no way for it to make any decision at all. The fundamental system design is that it guesses the word that is most likely to be next. That’s it. There’s no concepts behind whatever it outputs, it has no idea what it means.
It's a next-word predictor like a Markov chain, but a Markov chain couldn't do all the things ChatGPT does. ChatGPT has learned lots of syntax-level patterns pretty well.
I'm not sure what distinction you're getting at, but transformers do use "fill in the missing word" training and text generation chooses the next word (token actually) one at a time. Once it chooses a word, it doesn't go back.
You’re just nitpicking. Everybody here knows that it isn’t intelligent. Words can mean more than one thing. And in this case the word “learn” is being used to describe what ChatGPT does to improve its answers over time. It’s perfectly reasonable to say that ChatGPT needs to lean to say “I don’t know”.
There is no way for it to make any decision at all. The fundamental system design is that it guesses the word that is most likely to be next. That’s it. There’s no concepts behind whatever it outputs, it has no idea what it means.