If I learned MSA - would I be able to understand what people say in every Arabic country?
Non Arabs usually ask Arabs this question : If I learned MSA - would I be able to understand what people say in every Arabic country? - the answer to this question is : No, You wouldn't - because there are some differences between MSA and the dialects - but you will learn very quickly - because the differences are not big ones - And the dialects rules are very simple if you compare them with those of MSA
The problem is that Non Arabs usually ask the wrong people - and so - they got wrong answers - one of these wrong answers - the most famous - the one that people give without thinking - because they have only heard it from others - is : "You can understand Eastern dialects - but not Western ones" - Why? - "Because Western dialects are mixed with other languages -especially : French" - These answers are totally fals - all dialects differ from MSA - all contain lawn words - And if you understand MSA you can learn any of them very quickly
these are some examples to have an idea about the differences :
So I have a subsidiary question : If I learn MSA, most people in arabic countries should be able to understand me ? And if they take the care, they should be able to speak something close to MSA that I should understand ? As far as I have understood, MSA is taught in every arab schools.
I speak decent arabic from my parents and I can not understand any of what morrocans say, only like 5% random words. I think it is very different, it literally sounds like a different language to me. I think middle east, egypt/sudan dialects are much closer to MSA and easier to learn from MSA.
What do you mean by decent Arabic? - MSA or a certain Dialect? - if a dialect - which one? - If you have learned only MSA - you will not be able to understand any dialect - neither Moroccan nor Middle Eastern - and since you are not able to understand you cannot judge - you are only repeating what you have been told by middle eastern people - who are no specialist - and are not fair in their judgment!
As someone who learned MSA first and then the spoken I find all the dialects equally different and difficult tbh. I think the differences between Levant Arabic and Egyptian especially are often minimized by Arabic speakers, due to the fact that many Arabic speakers are already exposed to these dialects through pop culture and migration and take it for granted. Learning Lebanese Arabic when I had no experience other than Fusha and Iraqi Arabic was extremely difficult for me.
Unpopular opinion but my $0.02