Tamil phonology is characterised by the presence of "true-subapical" retroflex consonants and multiple rhotic consonants. Its script does not distinguish between voiced and unvoiced consonants; phonetically, voice is assigned depending on a consonant's position in a word, voiced intervocalically and after nasals except when geminated. Tamil phonology permits few consonant clusters, which can never be word initial.
The vowels are called uyire?uttu ('life letter'). The vowels are classified into short and long (five of each type) and two diphthongs.
The long (nedil) vowels are about twice as long as the short (ku?il) vowels. The diphthongs are usually pronounced about one and a half times as long as the short vowels, though most grammatical texts place them with the long vowels.
|Close||i ?||i: ?||u/? ?||u: ?|
|Mid||e ?||e: ?||o ?||o: ?|
|Open||ä ?||ä: ?|
Tamil has two diphthongs /a?/ ? and /a?/ ?, the latter of which is restricted to a few lexical items. [?] is found as a variation of /u/ at the end of words.
The consonants are known as meyye?uttu ('body letters'). The consonants are classified into three categories with six in each category: vallinam ('hard'), mellinam ('soft' or nasal), and idayinam ('medium'). Tamil has very restricted consonant clusters (for example, there are no word-initial clusters) and has allophonic aspirated stops. There are well-defined rules for voicing stops in the written form of Tamil, Centamil (the period of Tamil history before Sanskrit words were borrowed). Stops are voiceless when at the start of a word, in a consonant cluster with another stop and when geminated. They are voiced otherwise.
[n] and [n?] are in complementary distribution and are predictable, [n?] word initially and before [d?] and [n] elsewhere, ie they are allophonic.
/?/ is extremely rare word initially and is only found before /t/ word medially. [?] only occurs before [g].
The voiceless consonants are voiced depending on position.
Unlike Indo-Aryan languages spoken around it, Tamil does not have distinct letters for aspirated consonants and they are found as allophones of the normal stops. The Tamil script also lacks distinct letters for voiced and unvoiced stop as their pronunciations depend on their location in a word. For example, the voiceless stop [p] occurs at the beginning of the words and the voiced stop [b] cannot. In the middle of words, voiceless stops commonly occur as a geminated pair like -pp-, while voiced stops do not. Only the voiced stops can appear medially and after a corresponding nasal. Thus both the voiced and voiceless stops can be represented by the same script in Tamil without ambiguity, the script denoting only the place and broad manner of articulation (stop, nasal, etc.). The Tolk?ppiyam cites detailed rules as to when a letter is to be pronounced with voice and when it is to be pronounced unvoiced. The only exceptions to these rules are the letters ? and ? as they are pronounced medially as [s] and [r] respectively.
Some loan words are pronounced in Tamil as they were in the source language, even if this means that consonants which should be unvoiced according to the Tolk?ppiyam are voiced.
Elision is the reduction in the duration of sound of a phoneme when preceded by or followed by certain other sounds. There are well-defined rules for elision in Tamil. They are categorised into different classes based on the phoneme which undergoes elision.
|1.||Kutr iyal ukaram (short nature U)||the vowel u|
|2.||Kutr iyal ikaram (short nature I)||the vowel i|
|3.||Aiykaara k kurukkam ( AI shortening)||the diphthong ai|
|4.||Oukaara k kurukkam ( AU shortening)||the diphthong au|
|5.||Aaytha k kurukkam ( h shortening)||the special character akh (aaytham)|
|6.||Makara k kurukkam ( M shortening)||the phoneme m|
1. Kutr iyal ukaram refers to the vowel /u/ turning into the close back unrounded vowel [?] at the end of words (e.g.: '' (meaning 'six') will be pronounced [a:r?]).
2. Kutr iyal ikaram refers to the shortening of the vowel /i/ before the consonant /j/.