In phonetics, retroflex consonants are consonant sounds used in some languages. (They are sometimes referred to as cerebral consonants, especially in indology.) The tongue is placed behind the alveolar ridge, and may even be curled back to touch the palate: that is, they are articulated in the postalveolar to palatal region of the mouth.

Places of articulation
• Labial
Bilabial
Labial-velar
Labial-alveolar
Labiodental
• Bidental
• Coronal
Linguolabial
Interdental
Dental
Denti-alveolar
Alveolar
Apical
Laminal
Postalveolar
Alveolo-palatal
Retroflex
• Dorsal
Palatal
Labial-palatal
Velar
Uvular
Uvular-epiglottal
• Radical
Pharyngeal
Epiglotto-pharyngeal
Epiglottal
• Glottal

Retroflex consonants, like other coronals, come in several varieties, depending on the shape of the tongue. The tongue may be flat, with the blade of the tongue (the top surface of the tongue near the tip) touching the roof of the mouth, as in Polish cz, sz, ż (rz), dż and Mandarin zh, ch, sh, r. This is termed laminal (laminal retroflex). Or they may be pronounced with the tip of the tongue, as in Hindi. This is termed apical (apical retroflex). Finally, the tongue may be curled back so that the underside touches the alveolar or pre-palatal region, as in many of the Dravidian languages. This is termed sub-apical (sub-apical retroflex).^[1]

The consonants commonly called postalveolar, or more precisely palato-alveolar, such as English sh and ch, as well as the alveolo-palatals, such as Mandarin q, j, x, are also pronounced in the postalveolar region. However, they differ from retroflex consonants in having an additional secondary articulation of palatalization. The consonants commonly called palatal are pronounced in the palatal region like the sub-apical retroflexes, but they touch the palate with the back of the tongue, not the tip. (That is, they are dorsal, or more precisely dorso-palatal, rather than coronal consonants.)

In other words, retroflex consonants include various types of coronal consonants articulated behind the alveolar ridge which do not have the secondary articulation of palatalization.

Occurrence

Although data is not precise, about 20 percent of the world's languages contain retroflex consonants of one sort or another^[2]. About half of these possess only retroflex continuants, with most of the rest having both stops and continuants. Retroflex consonants are relatively rare among European languages, occurring in Sardinian, in Sicilian, some southern Italian dialects such as Calabrian and Salentino, in Swedish and Norwegian (where a sequences of r plus a coronal consonant may be replaced by the coronal's retroflex equivalent, e.g. the name Martin would be pronounced [maʈin]. Also, this is sometimes done for several consonants in a row after an r - Hornstull is pronounced [hoɳʂʈul]). The retroflex approximant /ɻ/ is an allophone of the alveolar approximant /ɹ/ in many dialects of American English, particularly in the Midwestern United States. Polish and Russian possess retroflex sibilants, but no stops or liquids at this place of articulation. Retroflex consonants are largely absent from indigenous languages of the Americas with the exception of the extreme south of South America and an area in Southwestern US, as in Hopi and Papago. In African languages retroflex consonants are also very rare, reportedly occurring in a few Nilo-Saharan languages. In southwest Ethiopia, phonemically distinctive retroflex consonants are found in Bench and Sheko, two contiguous, but not closely related, Omotic languages.^[3]

Retroflex consonants are concentrated in the Indo-Aryan languages and the Dravidian languages of the Indian subcontinent, where they occur as an areal feature apparently inherited from Dravidian (they do not exist in Proto-Indo-Iranian). They also occur in some other Asian languages such as Mandarin Chinese, Javanese and Vietnamese. The other major concentration is in the indigenous languages of Australia and the Western Pacific (notably New Caledonia). Here, most languages have retroflex plosives, nasal and approximants.

There are several retroflex consonants not yet recognized by the IPA. For example, the Iwaidja language of northern Australia has a retroflex lateral flap [ɺ̡] as well as a retroflex tap [ɽ] and retroflex lateral approximant [ɭ]; and the Dravidian language Toda has a sub-apical retroflex lateral fricative [ɬ̡] and a retroflexed trill [ɽ͡r]. Because of the regularity of deriving retroflex symbols from their alveolar counterparts, people will occasionally use a font editor to create the appropriate symbols for such sounds. (Here they were written with diacritics.) The Ngad'a language of Flores has been reported to have a retroflex implosive [ᶑ], but in this case the expected symbol is coincidentally supported by Unicode. Sub-apical retroflex clicks occur in Central Juu and in Damin.

Retroflex consonants identified by the International Phonetic Alphabet are:

IPA	Descrip-tion	Example
		Language	Ortho-graphy	IPA	Meaning
	retroflex nasal	Swedish	Vänern	[vɛː.neɳ]	Vänern
	voiceless retroflex plosive	Hindi	टापू (ṭāpū)	[ʈɑpu]	island
	voiced retroflex plosive	Swedish	nord	[nuːɖ]	north
	voiceless retroflex fricative	Mandarin	上海 (Shànghǎi)	[ʂɑ̂ŋ.xàɪ]	Shanghai
	voiced retroflex fricative	Russian Polish	жаба żaba	[ʐaba]	toad frog
	retroflex approximant	Tamil	தமிழ் (Tamil)	[t̪ɐmɨɻ]	Tamil
	lateral retroflex approximant	Swedish	Karlstad	[kʰɑːɭ.sta]	Karlstad
	retroflex flap	Hausa	shaara	[ʃáːɽa]	sweeping
ɺ̡	retroflex lateral flap	Pashto	ﻛړو	[kɺ̡o]	to do
ǃ˞	(voiced) retroflex click	Central Juu	—	[ɡǃ˞ú]	water

Note: In the International Phonetic Alphabet, the symbols for retroflex consonants are typically the same as for the alveolar consonants, but with the addition of a right-facing hook to the bottom of the symbol. Some linguists restrict these symbols for the "true" retroflex consonants with sub-apical palatal articulation, and use the alveolar symbols with the obsolete IPA underdot symbol for an apical post-alveolar articulation: [ṭ, ḍ, ṇ, ṣ, ẓ, ḷ, ɾ̣, ɹ̣]. Another solution, more in keeping with the official IPA, would be to use the rhotic diacritic for the apical retroflexes: [t˞, d˞, n˞, s˞, z˞, l˞, ɾ˞, ɹ˞]. Laminal retroflexes, as in Polish and Russian, are often transcribed with a retraction diacritic, as [s̱], etc. Otherwise they are typically but inaccurately transcribed as if they were palato-alveolar, as *[ʃ], etc.

See also

• Retroflex approximant
• Place of articulation
• List of phonetics topics

References