What are the common mistake that Arabs make when speaking English?

Verbosity and use of long sentences without breaks and full stops. Writing sentences that seems to be a direct translation of their mother tongue, most probably Arabic.

Use of the letter 'b' to signify 'p' as in Arabic there is no 'p'.

Some students or users of English rely on 'google translation' or other types of online translation or translation aids to assist them in building sentences or transferring the original message into the target language.

Other Arabic users do not know or fully grasp the concept of pragmatism or the use of the English language in context along with the nuances and cultural significance.

talk English words like the same way ( technique ) they do in Arabic  

____________________________

I can describe this as: Arabs speak English while keep thinking in Arabic. This leads to varied problems including internal translation and copying the Arabic speaking technique and, sometimes, accent and pronunciation.

Translating laterality from Arabic to English.

1. Arabic has no Be verb in present tense and no auxiliary Do.

The Be verb does exist in future and past tense forms, however, in the case of the Do auxiliary, the English language is pretty unique in having it. It's one of the few languages that use it. So, in an English sentence like, "What time do you want to do the homework?" might come out as, "What time you want to do the homework?".

2. Genitive constructions

Arabic expresses it only as possessed then possessor, while in English you have the choice to use an (of) construction, but it is more common use an ('s) where the possess item would follow the possessor and the possessor would have an ('s) suffixed to it. So in English, the idea of a man who possesses a car can be expressed by saying either, “the car of the man” or “the man’s car”, which does not exist in Arabic. 

3. Word order

In Arabic adjectives always follow the noun they qualify. So a car that is red would be expressed as “car red” in Arabic and “red car” in English.

4. Arabic is an inflectional language.

In Arabic, morphological markers may merge with the root of a word affecting its elements, or be affected by its elements. Arabic ha attached pronouns.

There are many others but those are more common.

Arabs make on different mistakes than other nationalities learing English ( or anything else ).

The only difference may be the use of British English in the Arab world vs US English.

In my view as normal as any other national "translating Arabic language to English" 

While doing this entire grammar collapse and then it becomes confusing. 

But to be honest, its too beautiful to listen Arabic English.

Speaking "English" in "Arabic".

They think in Arabic and they pay no attention to their pronunciation

I m with Mr. Jamal Udin for detail explanations and I m with Mr. Anayat Bukhari for the short term. I got involved with students from Arab who studying in here. And the common things are same with about the different constructions of sentence. Finally, they talk English in Arabic.