Arabic from the Quran in the old Hijazi dialect (Hijazi script, 7th century AD)

Some of the differences between Classical Arabic (CA) and Modern Standard Arabic (MSA) are as follows:

Since, throughout the Islamic world, Arabic occupied a position similar to that of Latin in Europe, many of the Arabic concepts in the fields of science, philosophy, commerce, etc. were coined from Arabic roots by non-native Arabic speakers, notably by Aramaic and Persian translators, and then found their way into other languages. This process of using Arabic roots, especially in Kurdish and Persian, to translate foreign concepts continued through to the 18th and 19th centuries, when swaths of Arab-inhabited lands were under Ottoman rule.

Classical Arabic is the language of poetry and literature (including news); it is also mainly the language of the Quran. Classical Arabic is closely associated with the religion of Islam because the Quran was written in it. Most of the world's Muslims do not speak Classical Arabic as their native language, but many can read the Quranic script and recite the Quran. Among non-Arab Muslims, translations of the Quran are most often accompanied by the original text. At present, Modern Standard Arabic (MSA) is also used in modernized versions of literary forms of the Quran.

Although Classical Arabic was a unitary language and is now used in Quran, its pronunciation varies somewhat from country to country and from region to region within a country. It is influenced by colloquial dialects.

Word stress is not phonemically contrastive in Standard Arabic. It bears a strong relationship to vowel length. The basic rules for Modern Standard Arabic are:

The restriction on final long vowels does not apply to the spoken dialects, where original final long vowels have been shortened and secondary final long vowels have arisen from loss of original final -hu/hi.

This is the most formal level actually used in speech. All endings are pronounced as written, except at the end of an utterance, where the following changes occur:

This is a formal level of pronunciation sometimes seen. It is somewhat like pronouncing all words as if they were in pausal position (with influence from the colloquial varieties). The following changes occur:

Adjectives in Literary Arabic are marked for case, number, gender and state, as for nouns. However, the plural of all non-human nouns is always combined with a singular feminine adjective, which takes the ـَة /-at/ suffix.

Nouns, verbs, pronouns and adjectives agree with each other in all respects. However, non-human plural nouns are grammatically considered to be feminine singular. Furthermore, a verb in a verb-initial sentence is marked as singular regardless of its semantic number when the subject of the verb is explicitly mentioned as a noun. Numerals between three and ten show "chiasmic" agreement, in that grammatically masculine numerals have feminine marking and vice versa.

Form II is sometimes used to create transitive denominative verbs (verbs built from nouns); Form V is the equivalent used for intransitive denominatives.

The spoken dialects have lost the case distinctions and make only limited use of the dual (it occurs only on nouns and its use is no longer required in all circumstances). They have lost the mood distinctions other than imperative, but many have since gained new moods through the use of prefixes (most often /bi-/ for indicative vs. unmarked subjunctive). They have also mostly lost the indefinite "nunation" and the internal passive.

The following is an example of a regular verb paradigm in Egyptian Arabic.

After Khalil ibn Ahmad al Farahidi finally fixed the Arabic script around 786, many styles were developed, both for the writing down of the Quran and other books, and for inscriptions on monuments as decoration.