While many languages have numerous dialects that differ in phonology, the contemporary spoken Arabic language is more properly described as a continuum of varieties. This article deals primarily with Modern Standard Arabic (MSA), which is the standard variety shared by educated speakers throughout Arabic-speaking regions. MSA is used in writing in formal print media and orally in newscasts, speeches and formal declarations of numerous types.
Modern Standard Arabic has 28 consonant phonemes and 6 vowel phonemes or 8 or 10 vowels in most modern dialects. All phonemes contrast between "emphatic" (pharyngealized) consonants and non-emphatic ones. Some of these phonemes have coalesced in the various modern dialects, while new phonemes have been introduced through borrowing or phonemic splits. A "phonemic quality of length" applies to consonants as well as vowels.
Modern Standard Arabic has six vowel phonemes forming three pairs of corresponding short and long vowels (/a, aː, i, iː, u, uː/). Many spoken varieties also include /oː/ and /eː/. Modern Standard Arabic has two diphthongs (formed by a combination of short /a/ with the semivowels /j/ and /w/). Allophony in different dialects of Arabic can occur and is partially conditioned by neighboring consonants within the same word. The following are some general rules:
/a, aː/
retracted to ɑ in the environment of a neighboring /r/, /q/ or an emphatic consonant (one that is uvularized, though customarily transcribed as if pharyngealized): /sʕ/, /dʕ/, /tʕ/, /ðʕ/, /ɫ/ and in a few regional standard pronunciations also /x/ and /ɣ/;
only in Iraq and the Persian Gulf: ɐ before a word boundary;
advanced to æ in the environment of most consonants:
labial consonants (/m/, /b/ and /f/),
plain (non-emphatic) coronal consonants with the exception of /r/: namely /θ/, /ð/, /n/, /t/, /d/, /s/, /z/, /l/, /ʃ/ and /d͡ʒ~ɡ~ʒ/
pharyngeal consonants (/ħ/ and /ʕ/)
glottal consonants (/h/ and /ʔ/)
/j/, /k/ and /w/;
Across North Africa and West Asia, the allophones [æ] and [ɑ] may be realized differently, either as [a ~ ɑ ~ ɛ], or both as [a ~ ä];
In northwestern Africa, the open front vowel æ is raised to ɛ or e.