Many translators do not care to have their work critiqued in the open, so I want to start by expressing my admiration for this work. Raja Abdallah (رجاء عبد الله ) translated the first two books, three and four by another translator, and each of the others had their own translators. I will not speculate on the reasons for the change, but I would have tried to stick with one translator for the entire series in order to keep a consistent voice. I have not read them all yet, just the first two, so I will have to address that as it comes. There are a few things that jump out at me as a reader from the very beginning of the Arabic version of the book. Most of which are negative and persist throughout the entire translation. Before I go into those things that I do not particularly care for, let is begin with the positive. I am sure no one will mind if I quote the first full paragraph:
Mr. and Mrs. Dursley, of number four, Privet Drive, were proud to say that they were perfectly normal, thank you very much. They were the last people you’d expect to be involved in anything strange or mysterious, because they just didn’t hold with such nonsense.
Here is the Arabic:

تفخر أسرة «درسلى» والتي تقيم في المنزل رقم 4 بشارع «بريفيت» بأنها أسرة طبيعية.. وهى فعلا كذلك، لا أحد نتصور أن تتورط مثل هذه الأسرة فى أية أمور عامضة أو مريبة!

And finally, a back-translation. I am going to perform these back-translations a bit more literally than I would normally want to do. This is to demonstrate the translation techniques used by Abdallah. I want to reiterate; I have great admiration for anyone who tackles the translation of a book, especially one as well-known and well-loved as Harry Potter. I will be pointing out differences in how I might have done it, but remember that I am not a native speaker of Arabic, and I would not even consider myself a very skilled Arabic writer. That is, after all, part of why I want to go through this exercise. Reading and analyzing these texts will help me develop my own skills. Hopefully I will gain an audience and start to hear feedback on my commentary. Back to the issue at hand:
The Dursla family, which resides in house number 4 on Privet Drive, is proud that it is a normal family.. It really is, no one would imagine that this kind of family would be involved in any strange or mysterious issues!
Here are the things you will notice, and I left them there on purpose to illustrate.

• Dursla – the translator here follows a convention that I have seen in many places and that I suspect is widely accepted. The Arabic letter ي ya’ in the final position gives the long “ee” sound, as in “Dursley”. The Arabic letter ى, without the two dots underneath, is actually an alif (the ‘ah’ sound), and not a ya’. This means that, were I to have read the Arabic version of the book before reading the English or seeing the movie, I would think the family name was “Dursla” not “Dursley”. As one proceeds, other Arabic words that must end in ya’ use the alif instead (fi, which means “in” is fa, ‘hiyya’, the feminine she or it, is ‘ha’, but these are obvious to any reader). Though it is widely used, I personally do not care for it. The two-dot version of the letter is under the “D” on the keyboard, the non-dotted alif is the letter “N”. No shifting or special characters required.
• Two dots, but a different kind: You’ll see that the first sentence ends with two periods instead of one. In my head this makes it feel like an incomplete ellipsis. I feel like the whole book is breathless and full of incomplete sentences because of this. This appears to be a publisher (and probably broader than the publisher) accepted form; each of the seven books uses the two-dot sentence ending (more frequently in the first couple of books, less so in the last book of the series). By contrast, the Arabic translation of Hunger Games uses only a single period to end a sentence.
• On punctuation, the translator seems to love exclamation points. Far more than J.K. Rowling does. This first paragraph ends with one. One could argue, I suppose, that it is for emphasis rather than exclamation; in that scenario the exclamation point takes the place of the phrase “they just didn’t hold with such nonsense”.
• Quotation marks. I applaud the use of the French-style chevrons rather than English-style quotation marks. I think they suit Arabic text much better, though it is a bit awkward to put them in (in Word and in Open/LibreOffice one must use insert symbol). On the other hand, reading further into the book we find that quotation marks are used around non-Arabic words, but are not used for actual quotations – real quotations have no special punctuation to separate them.

These are the issues in the first paragraph. They are present throughout the entire book; at least it is consistent! Consistency means that the reader’s eyes can adjust to these points, and move on.
Now to the point where I hang it all out here. Everyone feel free to laugh behind your hands or right out loud. Here is how I would translate this. I expect that my biggest problem here is going to be the one that most beginning translators (and, though I consider myself a professional – and have a certification from the American Translators Association – in translating from Arabic into English, I am a beginner when going into Arabic) suffer from: overly literal work.

يفخر السيد والسيدة درسلي، سكان منزل رقم 4، شارع بريفيت، بأنهما عاديين كاملين، وممتنان على ذلك. هم من آخر الناس الذين ممكن تتصورهم يتورطون في أمور غامضة أو عجيب لأنهم لا يقبلا سخافة من ذلك النوع.

Back translation:
Mr. and Mrs. Dursley, residents of house number 4, Privet drive, are proud to be completely normal, and they are grateful for that. They are among the last people you could imagine being involved in anything mysterious or strange because they do not accept that kind of silliness.
Or, at least, that was what I was going for.