Ḍād

Based on ancient descriptions of this sound, it is clear that in Qur'anic Arabic ḍ was some sort of unusual lateral sound.^{[1][2][3][4] [5]} Sibawayh, author of the first book on Arabic grammar, explained the letter as being articulated from "between the first part of the side of the tongue and the adjoining molars". It is reconstructed by modern linguists as having been either a pharyngealized voiced alveolar lateral fricative [ɮˤ]^ⓘ or a similar affricated sound [d͡ɮˤ] or [dˡˤ].^[2][3] The affricated form is suggested by loans of ḍ into Akkadian as ld or lṭ.^[1] However, not all linguists agree on this; the French orientalist André Roman supposes that the letter was actually a voiced emphatic alveolo-palatal sibilant /ʑˤ/, similar to the Polish ź.^[2][3][6] The reconstruction of Proto-Semitic phonology includes an emphatic voiceless alveolar lateral fricative [ɬʼ] or affricate [t͡ɬʼ] for ṣ́. This sound is considered to be the direct ancestor of Arabic ḍād, while merging with ṣād in most other Semitic languages.

The emphatic lateral nature of this sound is possibly inherited from Proto-Semitic, and is compared to a phoneme in Modern South Arabian languages such as Soqotri, but also in Mehri where it is usually an ejective lateral fricative. In Harsusi the counterpart to ض is mostly pronounced as lateral /ɬˤ/ (and its allophone [ɮˤ]), for example Harsusi /jeɬˤ.ħoːk/ vs. Arabic يضحك /jadˤ.ħak/ "he laughs", and Harsusi /ʔaː.reɬˤ/ vs. Arabic عريض /ʕa.riːdˤ/ "wide" but it also sometimes corresponds to Arabic ظ as in Harsusi /ɬˤa.her/ vs. Arabic ظهر /ðˤahr/ "back".^[7] In Shehri (Jibbali) it also corresponds to Arabic ض [mi.rəɬˤ] vs. مرض /ma.ri.dˤa/ "he fell ill", [ʕiɬˤed] vs. عضد /ʕa.dˤud/ "(upper) arm" and [ɛrɬˤ] vs. أرض /ʔardˤ/ "land", but also corresponds to Arabic ظ as in [ɛɬˤ.her] vs. Arabic اظهر /aðˤ.hir/ "show, reveal".^[8]

This is an extremely unusual sound, and led the early Arabic grammarians to describe Arabic as the لغة الضاد lughat aḍ-ḍād "the language of the ḍād", since the sound was thought to be unique to Arabic.^[1] While other Arabic grammarians like al-Dani have described the letter ẓāʾ ظ as "being unique to Arabs among other nations".^[9][10]

The corresponding letter in the Ancient South Arabian alphabet is ṣ́, and in the Geʽez script Ṣ́appa ፀ), although in Geʽez it merged early on with ṣ Sappa.

The standard pronunciation of this letter in Modern Standard Arabic is the "emphatic" /dˤ/: pharyngealized voiced alveolar stop [dˤ]^ⓘ, pharyngealized voiced dental stop [d̪ˤ] or velarized voiced dental stop [d̪ˠ].^[1]

In most Arabic vernaculars ض ḍād and ظ ẓāʾ merged quite early;^[2] in the varieties where the dental fricatives are preserved such as Najdi, Tunisian and Mesopotamian Arabic dialects, both the letters are pronounced /ðˤ.^{[12][2][3][5]} However, there are dialects in South Arabia and in Mauritania and the Sahrawi where both the letters are kept different but not in all contexts.^[2] In other vernaculars such as Egyptian ض ḍād and ظ ẓāʾ contrast; but Classical Arabic ẓāʾ becomes /zˤ/, e.g. ʿaẓīm [ʕɑˈzˤiːm] (< Classical عظيم ʿaḏ̣īm [ʕæˈðˤiːm]) "great".^[2][3][13]

One of the important aspects in some Tihama dialects is the preservation of the emphatic lateral fricative sound [ɮˤ], this sound is likely to be very similar to the original realization of ḍād, but this sound ([ɬˤ~ ɮˤ]) and [ðˤ] are used as two allophones for the two letters ḍād ض and ẓāʾ ظ.^[14][15] A study regarding the dialect of Rijal Almaa in southern Saudi Arabia has shown that the de-lateralization is apparent for the majority of speakers and more apparent among the younger speakers, and [ðˤ] is the most prevalent pronunciation for both ḍād ض and ẓāʾ ظ.^[16]

"De-emphaticized" pronunciation of both letters in the form of the plain /z/ entered into other non-Semitic languages such as Persian, Urdu, and Turkish.^[2] However, there do exist Arabic borrowings into Ibero-Romance languages as well as Hausa and Malay, where ḍād and ẓāʾ are differentiated.^[2]

ض is transliterated as ḍ (D with underdot) in romanization. The combination ⟨dh⟩ is also sometimes used colloquially. In varieties where the Ḍād has merged with the Ẓāʾ, the symbol for the latter might be used for both (eg. ⟨ظل⟩ 'to stay' and ⟨ضل⟩ 'to be lost' may both be transcribed as ḏ̣al in Gulf Arabic).

When transliterating Arabic in the Hebrew alphabet, it is either written as ד‎ (the letter for /d/) or as צ׳‎ (tsadi with geresh), which is also used to represent the /tʃ/ sound. The Arabic letters ṣād ص and ḍād ض share the same Semitic origin with the Hebrew tsadi.

In Judeo-Arabic orthography, it has been written as צׄ/ץׄ‎(tsade with holam), emulating Arabic orthography, where the letter is created by adding a dot to ṣād ص.

• Arabic phonology
• Sat
• Śawt
• Ḍ