ג different from Gimel
Pronunciation
In all varieties of Arabic, cognate words will have consistent differences in pronunciation of the letter. The standard pronunciation taught outside the Arabic speaking world is an affricate [d͡ʒ], which was the agreed upon pronunciation by the end of the nineteenth century to recite the Qur'an. It is pronounced as a fricative [ʒ] in most of Northern Africa and the Levant, and [ɡ] is the prestigious and most common pronunciation in Egypt, which is also found in Southern Arabian Peninsula. Differences in pronunciation occur because readers of Modern Standard Arabic pronounce words following their native dialects.
Egyptians always use the letter to represent [ɡ] as well as in names and loanwords, such as جولف "golf". However, ج may be used in Egypt to transcribe /ʒ~d͡ʒ/ (normally pronounced [ʒ]) or if there is a need to distinguish them completely, then چ is used to represent /ʒ/, which is also a proposal for Mehri and Soqotri languages.Historical pronunciation
While in all Semitic languages, e.g. Aramaic, Hebrew, Ge'ez, Old South Arabian the equivalent letter represents a [ɡ], Arabic is considered unique among them where the Jīm ⟨ج⟩ was palatalized to an affricate [d͡ʒ] or a fricative [ʒ] in most dialects from classical times. While there is variation in Modern Arabic varieties, most of them reflect this palatalized pronunciation except in coastal Yemeni and Omani dialects as well as in Egypt, where it is pronounced [g].
It is not well known when palatalization occurred or the probability of it being connected to the pronunciation of Qāf ⟨ق⟩ as a [ɡ], but in most of the Arabian peninsula (Saudi Arabia, Kuwait, Qatar, Bahrain, UAE and parts of Yemen and Oman) which is the homeland of the Arabic language, the ⟨ج⟩ represents a [d͡ʒ] and ⟨ق⟩ represents a [ɡ], except in coastal Yemen and southern Oman where ⟨ج⟩ represents a [ɡ] and ⟨ق⟩ represents a [q], which shows a strong correlation between the palatalization of ⟨ج⟩ to [d͡ʒ] and the pronunciation of the ⟨ق⟩ as a [ɡ] as shown in the table below: