Cha and Its Unaspirated Partner

Cha is the sixth of the thirty consonants and the aspirated partner of ca, the same palatal affricate released with a breath. It is a root letter with no orthographic duty: not a prefix, not a suffix, not a superscript, not a subscript.

Its interest is in how neatly it confirms a pattern. In modern Lhasa speech ca and cha have converged as a single aspirated affricate carrying high tone, exactly as ka and kha have converged in the line above and ta and tha will converge in the line below. The convergence is regular enough that a reader who knows what has happened to one line can predict what has happened to the others, and this is one of the reasons the alphabet is taught as a grid rather than as a list. The columns behave, and behaving is what makes them learnable.

The regularity also explains why Tibetan spelling looks harder than it is. Two letters that now sound the same are not an arbitrary redundancy; they record a distinction the language made when the script was designed and which a good many Tibetan speakers outside Lhasa still make. Spelling has kept a contrast that the prestige dialect has spent, and the alphabet is in that sense a document of the seventh century rather than a description of the twenty-first.