HAE learned more about English grammar by taking foreign languages classes than actual English classes?

Subjunctive moods, participles, perfect tenses...

I'm pretty sure I learned most of my English grammar by taking what I learned in Spanish classes and applying it to English.

And I kind of wonder why, but then again, I know several native speakers of Spanish and other languages who really have a hard time explaining their own grammar.

EDIT: Or replace "English" in the title with whatever your native language is. English isn't even my native language, but I learned it fairly young and thought it would apply more.

Also, I'm kind of surprised by how overwhelmingly the answers have affirmed this question. I guess most people learning their native language really don't get much instruction in grammar, but just go by the "feel" of it.