When Special Interests Collide: 9-1-1 & Linguistics Edition
Peruvian and Mexican Spanish are unique dialects - heavily influenced by local indigenous languages - where several words don't even sound similar to each other. An "accent" isn't going to be what trips Eddie and Buck up when talking to each other, it's going to be slang and regional differences.
Think soda vs pop vs sodapop vs soft drink vs coke or coca-cola vs lemonade vs Sprite vs other brand names for lemon-lime soda. All equally correct ways to refer to the same thing, varying only by dialectical context and specificity. (In some parts of the South, all soda is coke or coca-cola. In some parts of the world as a whole, all lemon-lime soda is called lemonade while lemonade itself is lemon juice. In my part of the world, all lemon-lime soda is Sprite.)
Some dialects are more common - almost everyone in North America who learns Spanish in school learns Northeastern Mexican Spanish with Texan influence and almost everyone in Europe who learns Spanish the same way learns Castilian Spanish.
(Eddie may have learned any of the 10 dialects of Spanish local to Mexico from his family or even a Texican variant from before the border changed. He may also be fluent in Spanglish, which is a structured code-switching system between Spanish and English, with some creole words thrown in where appropriate to its own internal rules.)
Andean-Coastal Spanish is the most common form spoken in Peru out of five recognized dialects, and it's extremely common in Ecuador as well but almost unheard of in the United States and Canada.
It's not just "saying words funny" or "sounding like the white boy he is". It's far more like a Scots English speaker talking to a Bostonian. Which I'm aware sounds exactly like "saying words funny" to the uneducated, but that's why I'm making this post. <3
An accent is how the oral posture (the way the parts of your mouth move) of your native language affects how you say words in a learned language. It can also be how the posture of your native signed language affects how you form signs in others, or how the alphabet of your native language affects how you write characters and symbols in another alphabet.
You can have a strong accent, but not a bad accent.
A dialect is a variation of a language, with its own grammar, syntax, and vocabulary similar but distinct from other dialects of the same language. Or, in rare cases, grammar or vocabulary completely different from other dialects! Most dialects of the same language are mutually intelligible, meaning you can understand what the person means even if not what they say.
You can speak a different dialect or mimic a dialect badly, but you cannot speak a wrong dialect.
A language is a system of communication with distinct, nuanced rules governing how - and sometimes in which situations - it is used. Most languages are mutually unintelligible, meaning the speaker of one cannot understand the other at all. If two languages are from the same language family, they may be partially intelligible instead, meaning you can get the gist or pick up keywords, but you cannot understand completely.
In addition to speaking a different language, you can speak a wrong language or speak a language badly, depending on the context.
TL;DR: Peruvian and Mexican Spanish are dialects of the same language, with similar but different rules and vocabulary, which Buck would speak with an American accent. As a bilingual person, if Eddie learned Peruvian Spanish, he would likely speak it with an American accent on some words and a Mexican Spanish accent on others. If Buck was speaking Peruvian Spanish correctly and Eddie was speaking Mexican Spanish, they would mostly understand each other, but not completely, and their accents would not affect that.
