When I was a child, I was brought up speaking/reading/writing both French and English. English in the morning, French in the afternoon - we were all bilingual, so it wasn't a problem. The thing was that in English, it was "look and learn" and you learned grammar without any real terms or rules, whilst in French, we had it all drilled into us. OK, sometimes it wasn't fun, but I remember my French grammar much better than the English one. I don't really remember English grammar other than punctuation and collective nouns!
. The French stuff on the other hand is stuck in my head, and is very helpful when learning Spanish when I was 60 onward...