Petrichor

Most definitely. I have started teaching myself a language in the past using various "Teach Yourself" style text books focusing on grammar, and later engaged native speaking tutors to learn how to speak in a more natural and idiomatic manner. It was a frustrating experience because I found the tutors frequently made grammatical mistakes, or simply didn't understand the structure of their own language at all, having picked it up instinctively since childhood. Perhaps those grammatical mistakes were correctly idiomatic according to some obscure rules not mentioned in the Teach Yourself books, but the problem was that there was no way of knowing for sure. My father learned English as a second language, and his knowledge of English grammar was always far superior to the general populace of England, even university students.