My first language was English. But while the teachers were busy trying to teach me to use correct grammar my mother was busy teaching me to play with it.
My mother was able to use good grammar but was aware of its history and aware of what other languages do. Fact is English can do amazing tricks -- But most of them are forbidden by formal grammar. Formal grammar is restricting and does more to deaden creativity in its users than it does to facilitate communication.
My second language was ASL.
Yes, I have always played with it too.