Stuff like this is interesting to me because it reminds me of how the human mind learns languages. I'm a language nerd of sorts. I only had 3 years of Spanish in school 30 years ago, I began re-learning on my own and then found a guy from Mexico that was interested in teaching me. For the past 3 years we have been meeting for breakfast on Sundays almost once a week, he's a 60 year old guy with a 4th grade education and came to the US in the 70's as a migrant farm worker. Without his help I never would have achieved the level of proficiency in the language, he has been without a doubt the most important resource for me in my journey. At this point in my teaching it's more or less us just going and talking and having normal conversation about whatever, and him stopping me if I make a mistake. I've stopped asking questions, to him anyway, because he simply can't answer them. At work, my neighbor is from Argentina, and has a Ph.D. in Physics and I will go to him with my grammar questions.
The point here that relates to the "of" and "have" is that most people do not realize what they are even saying when they speak. I have tried to get clarification from my Mexican friend on grammatical topics, and he can't usually explain the why's and in fact would have no idea of how to explain the why. It just sounds right/wrong to him. He gets confused at times and tries to b-s his way through an explanation, but he really doesn't know why do say this here and that there. Simple stuff early on in my learning sure - why do I use por here and para here. He could explain that pretty well, but my questions now are much more subtle. Now my Argentinean friend is better, he will often almost always be able to explain the rhyme or reason of a phrase and what rules it is following and why, but even he can get screwed up. One day I was asking him how to say something, and when he told me the phrase I said "Oh, that makes sense - it's using the subjunctive verb of X". He looked confused, and then said no that's a form of Y and then looked up and smiled and said, you are right! It's a form of X. He had been using this very common phrase his entire life without even realizing what verb he was using, and that's how we use language. Phrases just flow out, we don't break down things. The Subjunctive is very common in Spanish and gives English speakers fits. I understand theoretically when to use it, but I finally realized the only way to master it is to just get to the point where you "feel" it. Some things just sound "better" using the subjunctive form of the verb.
It is important that he try to study. If a non english person came to you and said why don't you use "It is important that he tries to study", could you explain that other than to say "well, just because the other way sounds right"?
How are Mexican and Argentinian Spanish different, jim? Like American vs English vs Aussie - same but just different accents and things like gas/petrol, toilet/loo, buddy/mate?
There isn't a great difference between Argentina and Mexico. Argentina has more of an Italian type accent, whereas Mexico is very clear. For me, Mexicans are the easiest accent to understand. Chile has to my ear the most pleasant accent - think of it as Spanish equivalent of urbanized South Carolina. Mexico is very crisp and clear and nasally, Chile is very soft and smooth. Argentina is somewhere between those two I would say.
The way the language is used in the Caribbean is pretty similar to the rest of Latin America, but the accent is very different and very difficult for me to understand. Puerto Rico, the D.R, and worst of all Cuba. They just don't pronounce certain things (they never pronounce the 's' at the ends of the words and the 'd' sound is very muffled like they have marbles in their mouths. Venezuela also has that trait.
Now Spain is completely different. Very different accent, different words, and a different way to use the grammar. Only in Spain do they use the second person plural (Vosotros), in the rest of the world they use the 3rd person (Ustedes). This is similar to the French spoken in Canada and in France - in Canada you use the 3rd person plural as well.
Not sure why, but there do seem to be more unique words to each country than you get with English. Some words can be very vulgar in one place, and perfectly normal in another. I suppose English is like that too.