A Letter That Carries Dialect Information

The lateral does more than record its own sound in the earliest Brahmi. Because the eastern dialects of the Ashokan period substitute it for an inherited r, its frequency in a given inscription is evidence about where that inscription was cut and what language was spoken there. A reader who notices an unexpected lateral in a word that Sanskrit writes with an r has found a dialect marker rather than an error, and the standard handbooks of Indian epigraphy set out the criteria in detail.

In its own right the letter is common enough in both Sanskrit and Prakrit vocabulary. It stands in a wide range of ordinary words and in several productive suffixes, and it is one of the four semivowels, standing third in that group between the r and the labial semivowel in the sequence that mirrors the order of the vowels the four answer to.

Its consonantal value is stable across the whole history of the script, which is not true of every letter: several signs shifted in value in one branch of the family or another as the languages changed around them. This one did not, and its Brahmi form stays recognisable in nearly every descendant alphabet, which makes it a useful fixed point when comparing two scripts that have drifted a long way apart.