For example reinforcement learning, like when AlphaZero famously learned by playing itself at chess and go and became much stronger than the purpose-built “alphago” first version.
Or another example generative adversarial networks where you have a generator network generating images and a validator network trying to spot fake images.
In both these examples it’s easy to see how you build the loss functions for the training because they are quite constrained. For a domain like a game you penalize versions of the model that lose games and reward those that win. For GANs the initial insight was huge but having had that it’s easy to see how you move forward - you reward the generator for slipping fake images past the validator and you reward the validator for finding fakes in a stream of images that includes some real images and some generated images.
For an open-ended general model like an LLM it’s not so easy to see how you do this in the general case. GPT models are actually pretty good at “zero shot” learning (without examples) and “transfer” learning (where lessons from a domain are applied to an associated domain).
Your example of a language is interesting, because you don’t learn your first language from any sort of teacher - you learn it from your parents and others talking around you and to you. So you have lots of examples to draw on. You then try out various sounds and words and everyone looks confused but becomes more excited as you get closer to saying something that is a real word eventually you hit on the magic recipe and say the word “DUCK!” (Or whatever) and everyone loses their minds. So you have lots of positive reinforcement that you’re on the right track and you have a huge number of examples. You’re not just fed the hackernews comment section, some papers on quantum mechanics and all the english literature that has fallen out of copyright and left to get on with it.
To summarise it quickly, Chomsky's contention was that all the world's languages can be described by shockingly few degrees of freedom on the same universal grammar, and that we learn language surprisingly fast relative to training data because all we are really picking up are those parameters and the rest is hard wired from birth the same way horses come out the womb already hard wired to gallop.
Decades later, very few things have truely stood the test of being universal among languages, but it was still a valuable contribution because he poked a serious hole in the pure Hebbian reinforcement theories which were in vogue back then.