Strictly speaking, there are two main groups of dialects spoken in the Hejaz region,[2] one by the urban population, originally spoken mainly in the cities of Jeddah, Mecca, Medina and partially in Ta'if and another dialect by the urbanized rural and bedouin populations.

In antiquity, the Hejaz was home to the Old Hejazi dialect of Arabic recorded in the consonantal text of the Qur'an.

Historically, it is not well known in which stage of Arabic the shift from the Proto-Semitic pair /q/ qāf and /g/ gīm came to be Hejazi /g, d͡ʒ/ gāf and jīm ⟨ج, ق⟩, although it has been attested as early as the eighth century CE, and it can be explained by a chain shift /q/* → /g/ → /d͡ʒ/[9] that occurred in one of two ways: * The original value of Proto-Semitic qāf was probably an emphatic [kʼ] not [q].

Furthermore, it has an eight-vowel system, consisting of three short and five long vowels /a, u, i, aː, uː, oː, iː, eː/.

Phonetic notes: Phonetic notes: Most of the occurrences of the two diphthongs /aj/ and /aw/ in the Classical Arabic period underwent monophthongization in Hejazi, and are realized as the long vowels /eː/ and /oː/ respectively, but they are still preserved as diphthongs in a number of words which created a contrast with the long vowels /uː/, /oː/, /iː/ and /eː/.

", أبغى /ʔabɣa/ "I want", ديس /deːs/ "breast" (used with the more formal صدر /sˤadir/), فهيقة /fuheːga/ "hiccup", and قد /ɡid/ or قيد /ɡiːd/ "already",[21] Other general vocabulary includes ندر /nadar/ "to leave" with its synonyms خرج /xarad͡ʒ/ and طلع /tˤiliʕ/, زهم /zaham/ "to call over" with its synonym نادى /naːda/ and بالتوفيق /bitːawfiːg/ "good luck".

A common feature in Hejazi vocabulary is portmanteau words (also called a blend in linguistics); in which parts of multiple words or their phones (sounds) are combined into a new word, it is especially innovative in making Interrogative words, examples include: The Cardinal number system in Hejazi is much more simplified than the Classical Arabic[22] A system similar to the German numbers system is used for other numbers between 20 and above: 21 is واحد و عشرين /waːħid u ʕiʃriːn/ which literally mean ('one and twenty') and 485 is أربعمية و خمسة و ثمانين /urbuʕmijːa u xamsa u tamaːniːn/ which literally mean ('four hundred and five and eighty').

Unlike Classical Arabic, the only number that is gender specific in Hejazi is "one" which has two forms واحد m. and وحدة f. as in كتاب واحد /kitaːb waːħid/ ('one book') or سيارة وحدة /sajːaːra waħda/ ('one car'), with كتاب being a masculine noun and سيّارة a feminine noun.

Changes to the vowels in between the consonants, along with prefixes or suffixes, specify grammatical functions such as : Hejazi has two grammatical number in verbs (Singular and Plural) instead of the Classical (Singular, Dual and Plural), in addition to a present progressive tense which was not part of the Classical Arabic grammar.

Combinations of each exist:[24] According to Arab grammarians, verbs are divided into three categories; Past ماضي, Present مضارع and Imperative أمر.

An example from the root k-t-b the verb katabt/ʼaktub 'i wrote/i write' (which is a regular sound verb): While present progressive and future are indicated by adding the prefix (b-) and (ħa-) respectively to the present (indicative) : Example: katabt/aktub "write": non-finite forms Active participles act as adjectives, and so they must agree with their subject.

General Modifications:- Medial vowel shortening occurs in Hollow verbs (verbs with medial vowels ā, ū, ō, ē, ī) when added to Indirect object pronouns:[28] Hejazi does not have a standardized form of writing and mostly follows Classical Arabic rules of writing.

However, the speech of some tribes shows much closer affinity to other bedouin dialects, particularly those of neighboring Najd, than to those of the urban Hejazi cities.