Don’t be surprised if you have studied Spanish for years and then one day you are in the middle of a party somewhere in Mexico and you have no idea what anyone is saying.
You don’t even have to be in Mexico for this to happen. But if you learned Spanish in public schools in the US, like me, and then traveled to Mexico (or the part of your town where the really good tacos are), then you must know what I’m talking about. Mexicans from all walks of life use a huge amount of slang.
In school I remember lists of verb conjugations. How boring. When you get to Mexico, one of the first things you may realize about the language is that the “vosotros” form is completely useless.
Another very important thing to know, maybe the most important, is that in Mexico when you don’t understand someone and have to ask “What?”, you don’t say “Que?”, you say “Mande.” I’ve traveled to quite a few countries in Latin America (Spain too), and Mexico is the only place they use this word. But they use it all the time.
Also, be prepared for lots of bad language, “groserias,” especially around men. Keep that in mind - certain words will get you huge laughs in drinking parties full of guys, but could deeply offend the pretty girl you are trying to meet.
One of these words you will hear around guys for sure is “Wey.” It means dude, but it is overused like how an American teenage girl overuses “like.”
This heavy use of slang is especially true in Mexico City, which they call D.F. - you pronounce it “day-ef-eh.” Almost no one says, “Cuidad de Mexico.”
Remember, when you don’t understand, don’t sulk or despair – simply ask. “Mande?”