Are those of you who have managed to grasp the intricacies  of English grammar, equally as capable with mathematics?

I'm an American, but grew up in Hawaii.  English was my first language, but there were two modes - standard (US) English, and the colloquial pidgin that most people spoke when casual.  I never had interest in the formalities of grammar - diagramming sentences, which was the plural verb, and so forth.  But I could speak and write reasonably well just by emulating what I read in books or heard on TV.  I couldn't explain why it was "brought it to him" rather than "brang it to he," but one of them just sounded right.  Grammar has a lot of rules, and exceptions are no more than narrow rules.  But I think the main point of language is to communicate, and don't mind butchering English or any other language as long as the point gets across.

I was always good at Mathematics.  There are less exceptions.  But like grammar, I often forget the formalities of why the limit of sin(x)/x is 1 as x goes to 0, but know the right answer.

I'm an American; I personally think that having a command of both stems from having a good understanding of logic, a subject that lower-level U.S. schooling never explicitly touches on although it obviously should. If it did, we wouldn't have so many inane conspiracy theories occupying people's minds.

I was very good in English- that's what my BA is in, with philosophy as the minor. I was horrible in algebra and geometry classes in high school, but taught myself algebra in chemistry classes. I also found myself perfectly capable of helping my son when he needed it with his geometry homework.

That brought me to a realization that I could have, in fact, mastered any mathematics if I had had any interest in it. Of course, I had to study formal logic in philosophy classes- that was what I was lacking in high school. On a side note, I also found that having studied logic made learning computer programming quite easy.

My interest however, has always been in the humanities, not physical science.

Hard to say. The last time I took an exam to measure proficiency in both (GRE), I scored in the 99th percentile in both. The exam did not measure proficiency in the physical sciences; I took the one in Biology.

I was born and raised in the USA.

I love the English language, but I'm not a big fan of maths.