Devanagari Ca च

Ca is the sixth consonant of the varnamala and the head of the second varga, the palatal class. It is voiceless and unaspirated, made with the body of the tongue against the hard palate, and it is conventionally transliterated with a bare c although English speakers hear it as the ch of church. The palatal class stands second because the varnamala runs from the back of the mouth forwards: the velars are made furthest back, the palatals next, and everything else is made further forward still.

The Sanskrit phoneticians named the class talavya, from the word for palate. The class shares its place of articulation with the vowels i and long i, and that is not an incidental parallel. The grammarians classified vowels and consonants by the same criteria and used the correspondence in their rules, most visibly in the rule that turns i into the palatal semivowel ya when a dissimilar vowel follows. Sound changes in Sanskrit run along these class lines constantly, and a reader who knows which class a sound belongs to can predict a great deal of what happens to it at a word join. That predictive value is the practical payoff of arranging an alphabet by articulation instead of by inheritance. It is also among the letters most often mis-transliterated in popular writing, where the bare c of the scholarly systems is replaced by ch and the aspirated letter that follows it by chh, so that a reader meeting both spellings has no way to tell which of the two Devanagari letters is meant.

The palatal class has a history that was worked out in the nineteenth century and that reshaped how the relationship between Sanskrit and the European languages was understood. Sanskrit palatals correspond, in related words across the family, to velars in Greek and Latin, and the correspondence turned out to be conditioned: the ancestor language had velars, and those velars became palatals in Sanskrit when a front vowel followed. Establishing that also explained a puzzle about the vowels, since Sanskrit has a where Greek and Latin have e, o and a in the same words, and the palatalisation shows that the distinction those languages preserve must once have been present in the ancestor of Sanskrit too and was lost afterwards.

The finding is one of the foundations of Indo-European linguistics and is set out in the standard handbooks. For the alphabet, the consequence is that the second varga is a later development in the language even though it holds an early place in the table, which is a reminder that the varnamala orders sounds by how the mouth makes them and not by when they arose. The atlas records the class's articulation and position as attested; the historical account belongs to comparative philology and is cited to that literature rather than asserted as a property of the letter.