story
You’re viewing it the wrong way around. L1 speakers almost never use formalized grammar rules (especially not in everyday speech). Instead, the rules are formulated post-hoc based on the way the language is actually spoken.
In a sense, there’s no ‘correct’ or ‘incorrect’ language use, only successful or unsuccessful attempts at communication.
For this reason, I find the topic of input-based language learning interesting. The basic idea is that the only true way to acquire a language is by getting a lot of input (i.e. immersion), not by studying grammar rules.
(Disclaimer: not a linguist.)