I can tell you that it depends. For instance, my family is algerian and I grew up with the algerian dialect of Arabic....however, there are certain regions that share a very similar dialect to each other, with a few words differences of course but overall they have the same style of speaking among the countries of the regions. I'll break it down: The Levant (Lebanon, Palestine, Syria, Jordan): they can communicate with little difficulty. The Gulf-Khaleej (Saudi Arabia, Yemen, Kuwait, Qatar, etc.): This accent generally consists of more emphasis on the letters than does the Levant accent. Also, some of the letters are pronounced differently. For instance, here in algeria , we would call "heart" "9alb"with ق. In khaleeji, they would call it "galb". There are also other differences. For that reason, for ME personally I have a harder time understanding them. Also you can probably include Iraqi dialect as being very close to the Gulf accent, although technically Iraq isn't considered in the "Gulf". Egypt: Egypt kind of stands alone with its accent. It is pretty much recognized by the majority of the Arab world, and popular in songs, shows, etc.This makes it easy for a lot of Arabs to understand it. A primary feature of the Egyptian dialect is that they pronounced "jeem" (ج) as a "g" like in "glass" instead of "j" like in "jack"...( not because peoples in egypt talk العربية الفصحة it's because their songs and shows and movies are very popular in arab's countries ) North Africa ( where I am :) (Tunisia, Morocco, Algeria, etc.... Its accent is completely different): Much of the North African dialects are heavily influenced by French, and mixed with Arabic. It is probably the most different from Arabic and all the other accents and therefore a lot of outsiders have a hard time understanding our countries' accents. :p Those are basically the regions. Like I said there are still of course differences among the countries, even if they are in the same region. But overall, the countries in each region have similar dialects, where the people are able to communicate among themselves with less difficulty. As soon as we start exiting these regions, communication becomes more complicated. However the level of understanding of each dialect really depends on the person. For instance, some Arabs can understand North African dialect with concentration. Also if an Arab knew French they would more easily understand this dialect. Although Arabs usually try to communicate with each other in their own slang dialects, even if they are from different regions, if communication is extremely difficult, they may switch to Fusha (Formal) Arabic, which is the standard Arabic of all regions and appears in writing such as newspapers and books.

Hello, I did talk a lot about this topic "the dialects in Arabic". Now, about the origin of the standard Arabic, we are not sure about everything, it has some searches say that's the origin from "قريش المضرية العدنانية something about saying of my friend at the first, I did talk to lots of Saudi Arabia, and they speak differently than the standard, and also it has some different accents which are more far from the standard one , perhaps you have seen lots of movies talking in Saudi Arabia accent, but you have to know it's the simple and not the real accent using in daily life. also for Moroccan, we do simplified our accent on the movies. But in real it's different. For us, in Morocco, we do understand the other dialects in fact watching movies and series ext... But for us, it has no famous movies to watch that's why the Arabs cannot understand us well. I have done a small lesson talking about the dialects in Arabic, perhaps if you're interested more, i can send it to you. # Please everything's done from my friend "mblaq310792 ", she explained very claire to you

I'm from Morocco and I can understand all the dialects of the Arab countries! the problem is that the Arab fossha is never used in everyday conversation! however, to answer your question, I will speak an Arab that is understandable to both! a mixture, just to understand each other :) (I'm sorry if I made some mistakes but I'm here to learn)

the alfusha is base on saudi dialect. no matter where arabe from they can more or less understand fusha (not neccessary them to speak good fusha,but they can understand better). all over the dialects lean and modified their dialect toward alfusha when they come to encounter different dialects into one another. May the experts correct me if i got wrong

It depends on the person if he is exposed to the other dialects. Those who watch TV shows of other Arab nations can understand their dialects because they learned it through their TV shows/dramas, and the common ones are Egyptian and Levantine. North African dialects such as Libyan, Moroccon ..etc. are the hardest for those who did not mix with those speaking it since there aren't as many shows/dramas in those dialects, or they are only found in their own channels and not channels of other nations, contrary to Egyptian, Syrian ..etc. I am from Libya and can understand most dialects, though I find it difficult to understand Moroccon and Algerian dialect, depending on how fast they speak and if they mix some fus-ha with it or speak purely in their dialect. For anyone who is learning Arabic, the best thing to do is learn fus-ha فصحى (Modern standard Arabic) because no matter what Arab country you go to, everyone who has gone to school, or learned how to read and write (i.e. is not illiterate), understands fus-ha, and can speak it well enough (not necessarly perfect) for others to understand it. And when you speak to them in fus-ha with some foreign accent, they will know that you are a foreigner, and most will probably get the hint to speak to you in fus-ha, especially if you tell them that you "didn't understand" (لم أفهم).