As I mentioned before, I owned a coffee shop/bakery in San Jose del Cabo for several years. We had Mexican employees of course and our place became very popular with the local Mexican residents. You can imagine that I was trying to improve my speaking skills quickly.
If you've never lived in a foreign country and tried to learn the language, the first thing you need to know is that you can't always translate the words and expect the same meaning. Naturally the culture of the country affects the significance of the words and phrases. For example, the word "stupid" in English is pretty harmless. We will say "That's really stupid" and mean that something was frustrating or planned poorly or something. Down here, the same word is a HUGE insult. "Stupid" here means like you're an uneducated backwoods hick Indian that eats snakes and donkey dung and makes human sacrifices. Or something like that. Trust me, don't even use the word out loud unless you know who you are talking to and they know you. After having a few people like clerks and secretaries look at me like I was the most rudest human being in the world, I asked some questions and got straightened out!
Another thing that happens here is that we English speakers have a tendency to guess at words. Maybe we hear a conversation with familiar sounding words and hey! we're not Stupid for crying out loud! So we store up a couple of words for the right moment and then spring 'em on the poor unsuspecting Mexican who gives you the "look." (You'll know it when you see it)
Here's a couple of examples from Yours Truly who has bludgeoned the local dialect unrecognizable. Take the English word "embarrassed." I heard a word said in a sentence that had to be "embarrassed." It is the Spanish word, "embarasada." Sounds right, right? So after I told a Mexican friend that I was "embarasada" about something, he laughed and "How far along are you? Embarasada means pregnant." So far, not too embarrassing. Another word is "exitado." Sounds like "excited" no? Well yes, excited but in a sexual way. I misused that one too. It gets worse. This one is like WAY embarrassing. I used to confuse 3 words: miedo (fear), marido (husband) and mierda (the worser word for poop.) I was trying to ask an employee "How was her husband." Guess what I asked her. I didn't realize my error until I saw the "look." It was a doozy.
I will say with all gratitude that Mexican people are extremely forgiving when it comes to language. If you give it your best shot, normally a Mexican will go out of their way to help you communicate. It's a beautiful thing.