Formality and standardized grammar.

At some point, when you’re involving teaching a language to a class, you need a systematic way of doing so.

Typically, that means going with dictionaries and that in turn is likely to be the most formal version of a language’s pronunciation. And, with grammar, you start with the simplest but also most standardized, codified version because that’s what the books are going to use.

You don’t worry about idiom and dialect until you’ve got a fairly good grasp of the formal. Since Castilian Spanish is more or less the oldest formal Spanish, we end up learning that first.

Like, I suck at learning languages. But I tried several. One of those was Spanish. School Spanish is kinda like school English, it’s taught in strict way. Vocabulary with pronunciation, grammar rules, verb conjugation. Conversationsal Spanish just isn’t what most schools are going to start with. One could argue whether or not that’s the best place to start or not, but it is the way most languages get taught.

I dated a girl from Mexico City during that time, and she said the books were essentially the same there at least.