All Arabic spoken now all over the Arabic world is a different local dialects which called ( ammiyah ). These dialects are different than Arabic which we read and write ( Standard Arabic ) which called ( Fusha ). The Holy Quran is in Fusha so anyone wants to read the Holy Quran should learn standard Arabic ( Fusha ). Arabic which is used in prayer is Standard Arabic as well.

First and foremost God bless you for such a question, it does warm my heart to learn that, there are people out there willing to learn Arabic just to read the Quran, matter fact I have an American friend that I always tell him this " I pray you learn Arabic the way I do just to read the Quran" therefore God bless you,help you, and I'll pray for you. now back to your question, see nowadays we speak modernized Arabic, or you can call it a local slang, we don't care about the grammar no more, that's unfortunate obviously, in my country we speak in different ways, just like every other country, every city has its own way of talking, and most of the time you can see it's grammatically incorrect, but no one cares as long as its not mandatory. look at it this way, if you look up Shakespeare work, and compare it too, lets say John Green's work, you think they speak totally different languages! the choice of words is different, the word play is different, the sound is different, the Quran comes with the most perfect Arabic ever, even the Arabs at that time could not even criticize a word of it, that's why we have a lot of meaning, and explanatory books to translate the Quran, I am an Arabic native speaker, I live in Mecca, the center of Islam, and yet I struggle many times with some verses, and to say even more, there is a huge chunk of our society that does not understand most of the Quran, once again God bless you, keep pushing, you'll get it soon enough, and excuse my poor English, and if you ever need help with anything, just let me know.

There are a handful of dialects in Arabic. Learning anyone of them should still allow for you to understand the Quran or be able to piece together what you are reading or hearing. Yes after some practice you be able to understand people reciting the Arabic Language. Most Islamic religious terms are direct borrowings from Arabic, such as صلاة salat 'prayer'.

The Arabic in the Holy Quran is n`t different , The difference is we are talking in slang but the Holy Quran is written and Spoken in classical

Well, this question can be remodeled that you need an overview of Arabic. Here it is. People speak nowadays many dialects of Arabic that are simple but the language of written books , official papers and serious TV programs such as the news are all in modern classic Arabic. It is the language of education so every child learns it. Even illiterate people are able to understand it but can't use it perfectly as it requires knowledge about grammar that is quite different from the local dialects. As for the language of Quran , it is in fosha "classic Arabic " with the same grammar but the vocabulary is a higher level you can get a sense of it if you imagine Shakespeare's vocabulary in relation to your current English. The way we read Quran is unique we have to apply certain rules,for example, certain letters are pronounced differently when they come adjacent to some other letters.This is not done with any other reading even the prophet's sayings. We are religiously asked to read it that way and when you listen to Quran you will find this feature. However many people including Muslims can't do this and read it as they do with other books. The meaning will not change but you shall miss the soul of the Quran and of course if you are an Arabic Muslim without an excuse you will not get the full awards form God