Brahmi Tha 𑀣

The two-letter spelling used for this consonant in European scholarship has misled generations of readers. It is not the th of English think, and not the th of this either; neither of those sounds occurs in Sanskrit at all. It is a single dental stop released with a following breath, and the roman spelling is a convenience that happens to collide with an English digraph. The Brahmi letter makes no such promise, because it writes one sound with one sign and the question of how to spell it in another alphabet never arises.

In the language the letter does specific work. It is the ending of the second person plural of a large class of verbs, so a sentence addressed to several people carries it, and it appears in a set of common nominal suffixes besides. In the Prakrit of the Ashokan edicts it is frequent, because a family of inherited clusters simplified to an aspirated dental as the language moved into its Middle Indo-Aryan stage.

That change is one of the regular correspondences by which a Prakrit form and its Sanskrit counterpart are matched, and it works in both directions. An editor reading a damaged word in an edict can often say what the Sanskrit behind it must have been, and a reader who knows only Sanskrit can learn to convert as they read. The handbooks of Indian epigraphy teach exactly that skill, and it is why they devote as much room to Middle Indo-Aryan phonology as to the letters.

Brahmi writes aspiration everywhere and consistently, which is a choice, and it is worth setting beside the things the script declines to write. It does not mark the difference between the voiced retroflex stop and the flap it weakens to between vowels. It offers no explicit sign, in its earliest form, for a consonant with no vowel after it. It leaves a good deal of vowel quantity to be recovered from a worn surface. Aspiration it never leaves to the reader, in any period, in any regional hand.

The reason is that aspiration is contrastive across the whole vocabulary in both Sanskrit and Prakrit, so a script that dropped it would produce genuine ambiguity in ordinary words rather than the kind a reader can resolve from context. The features Brahmi leaves unwritten are the ones a competent speaker of the language could supply without effort. That is the ordinary economy of a writing system used by people who already know the language it records, and it is the reason a script developed for its own speakers can look under-specified to a foreign scholar reading it two thousand years later.

The descendant scripts gradually became more explicit as the situation changed. A manuscript tradition copying texts in a language no longer spoken has different requirements from a mason cutting a proclamation for people who speak it, and the additional marks appear as the need for them appears.