Two R Sounds, Held Apart

Tamil distinguishes two r sounds where Indo-Aryan has one. The inherited letter writes a flap made behind the teeth; this additional letter writes an alveolar sound made further forward, and the two separate ordinary words in the language, so a script serving Tamil cannot manage with the single sign it received from the north. The distinction is Dravidian and it is one of a set that the northern alphabet had no reason to provide for.

The letter also carries a use that has no counterpart in the inherited system. Written double, it is pronounced not as a long r but as an affricate, a stop released into a fricative, and written after the alveolar nasal it produces a further cluster that Tamil treats as a unit. A reader coming to Tamil from a northern Indic language finds those values counter-intuitive, because the relation between the doubled letter and the single one is not the ordinary relation between a long consonant and a short one.

Modern Tamil keeps the letter, and so does Malayalam. The other Dravidian literary languages have lost the distinction it marks or record it differently, so its presence in an alphabet is one of the ways the southern branch of the family divides internally rather than merely differing from the north.