My experience with learning Latin was about as opposite from my experience with Chinese as possible. But my coworker learning Old Norse and my old brief period with Inuit made me think of "useless" languages, and my five years with Latin was certainly anything but useless.
I was stuck in Latin class because we moved when I was in junior high and my old school system didn't start language courses until the eighth grade (well, I had like a teeny semester of a really simple Spanish "class"), but the the new school system started students in French or Spanish the grade before I moved in, so kids in my grade had spent their seventh grade on the first semester of a language, and the eighth grade would be on the second semester. So... for us newcomers, it was Latin or reading. Phew.
But by that time, I was already realizing there was a difference between not only what
but how we were studying and how my peers were studying their languages. They were already like, learning to speak and having some conversations and talking about the cultures of the countries where their languages were spoken. What I got was more a history class with a heavy language focus, or as close as an eighth grader could get to like, Archaeology or Roman History 101.
I don't even remember how exactly how the grammatical concepts of Latin were actually introduced, but I'm pretty sure they're not in the way I think of them now. And in thinking of that, I realize that our Latin teacher's challenge was not only to teach us Latin, but to teach us English... sort of.
If you started throwing around things like dative case, ablatives, reflexive and demonstrative pronouns, voice and mood of verbs, and all the rest in a room of adults, not many of them would know what you're talking about, much less a room of fidgety 14 year olds (is that how old eighth graders are?) So that was the first time I really became familiar with those concepts in my mother tongue. And maybe that's the whole focus of this post... that realization.
I've been surprised at how many people here have, when asked about Chinese grammar (to make a point, not an inquiry), have replied to me with something to the effect of "Does Chinese have grammar?" What is grammar?
Grammar is just the laws of the way the bits of your language interact, how the main constituents fit together and work with each other to represent ideas. (Also, and this is for another time, but the more you spend time in translation or language study, the more you realize that language is just weird... and very abstract and incredibly subjective... I digress.)
Every language has words, and every language has verbs and some kind of sentence structure, and nouns, and many of the concepts that many of us are all familiar with, but in some ways that's like saying that Mongolia and Monaco both have food and people and land so someone from one could move to the other with no problem. Not so. They're fundamentally different. But you could certainly learn to get by in the other.
The illustration I use is this... Think of a city map. My hometown has a perimeter (ring road) highway, and highways dissecting it from north to south, east to west, NE-SW, and NW-SE, so those are what most people use to get from one big section of town to another, and then from there it's surface streets. This is an idea I became pretty used to driving around in my city, but it only works in my city. You can't rely on that system if you're going to go to Chicago or New York or Portland or Dallas, but that's not to say you can't get to anywhere in the city somehow. Just because I can't take one highway in one direction then another highway in another direction doesn't mean its impossible to get there. You just have to work around its infrastructure, and you'll eventually get used to it if you spend enough time there.
But if you've never even looked at a map of your own city, understood directions and distances and point A to point B stuff with places and areas you're familiar with and know well, you won't have much chance in a foreign city with foreign surroundings and a foreign map.
Language is the same! One of the biggest aids that Latin gave me was becoming incredibly familiar with the grammar and infrastructure of my mother tongue. None of us are ever taught that kind of thing in school; we just learn that it's "I go," but "I went," and "she goes" and all that. We just know it is so, but we don't visualize charts for person, number, tense, voice and mood. We don't actively conjugate in our heads. And maybe that's just because we're English speakers.
Latin has very specific and stringent rules for everything in the language, and if my notebooks weren't 9,000 miles away, I'd snap some photos. It's all incredibly detailed, and that's just a concept that many English speakers aren't familiar with. What I found myself doing in Latin is learning about the prepositional case or the imperative mood or something and then asking myself "what does this look like in English?" And that was incredibly educational.
The difference between Latin and Chinese learning for me was that all my Chinese learning was done on the street, in restaurants and with neighbors and friends and very haphazardly, but it was live and interactive and real. Latin was sterile, classroom, analytical memorization.
You know how in math class when you're given a problem to solve with no context and you solve for x and get an answer and it has no real meaning? But then that same problem can be put in a real life context of like... "Max wants to build a house..." and using trig functions to solve for the length and slope of the roof or whatever feels productive and satisfying because it has real world application? We didn't have that in Latin. What felt like the real practical use of the language was translating text. That felt like we'd gotten to the real thing, but even that was just... busy work. The worth of Latin was in putting my own language into perspective, and understanding that for the most part, every language has a way of communicating certain relationships between their terms, whether as simple as subject-object or the agentive case or one of any other ridiculous cases that Finnish and Hungarian have. All languages, no matter how indirectly or directly, tend to have some way to show these things somehow, and it's helpful to relate the concept in your mother tongue with that same concept in the target language, no matter how differently they're treated.
It was a hell of a lot of brain work to get my head around all that, but once it's there, most every other language is made significantly more familiar, if for no other reason than you can actually practice speaking it with other people.
I have so many more ideas in my head about Latin, and how it was a tremendous help when I started going after Italian, or French (far less studiously), but it was what taught me about my mother tongue. It's a hell of a boot camp for most grammatical concepts, and they become familiar through boring translation work like we did.