Typing Tamil: the layout that did not join InScript

The one Indian script that went its own way

InScript is the Indian government's keyboard standard, and its cleverest property is that it is not one layout but a family: the phonetically equivalent letter sits at the same position in every script that belongs to it. Learn it for Devanagari and a Telugu or Gujarati keyboard is already half familiar.

That is a claim this site can check rather than repeat, because Unicode lays the Brahmic scripts out in parallel — the letter at Devanagari's offset 21 is the equivalent letter at Telugu's offset 21. Subtract each script's block start from what its keyboard produces and you can ask, key by key, whether two layouts agree about where a letter goes.

The answer is the table below, and it is emphatic. The InScript layouts agree with Devanagari on almost every key they define. Tamil agrees on two.

Sinhala is in the table for the same reason: it uses Wijesekara, its own arrangement, and it is the other script here that never joined.

Why Tamil could afford its own design

The usual telling of this is political, and the interesting part is not. Tamil has a genuinely different problem to solve from the one InScript was designed for.

Tamil has 18 consonants. Sanskrit-derived scripts typically have more than 30, because they distinguish aspirated from unaspirated and voiced from voiceless in writing — four letters where Tamil has one, with context telling the reader which is meant. A layout arranged around a 33-consonant inventory is carrying keys Tamil does not need, and spending positions on distinctions Tamil does not write.

Tamil 99 was designed in 1999 around Tamil's own letter frequency and is the Tamil Nadu government standard. Having a smaller alphabet to place is what made a cleaner arrangement possible at all.

Vowels left, consonants right

The arrangement is the part worth knowing before you start, because it makes the layout much easier to hold in your head than a set of unrelated positions.

Every key under the right hand produces a consonant. Every key under the left produces a vowel, apart from one consonant and the pulli — the mark that strips a consonant of its inherent vowel. So an ordinary Tamil syllable, which is a consonant followed by a vowel, alternates hands by construction.

If that sounds familiar, it is the same property Korean's Dubeolsik has and for the same reason: when a writing system alternates two categories, a layout that separates those categories by hand gets hand alternation for free. It is a much rarer piece of luck than it sounds — most layouts have to chase alternation by shuffling individual letters.

The practical effect is that Tamil 99 is learned in two halves rather than as thirty separate facts, and the half you are in tells you which hand to move.

The alternatives, and who uses them

Tamil typists are divided in the way typists always are. Besides Tamil 99 there are phonetic layouts, which map Tamil letters onto the Latin keys their transliteration suggests, and typewriter layouts inherited from mechanical machines.

The arguments are the ones this site keeps meeting. A phonetic layout is quick to start and is not installed on anyone else's machine. A typewriter layout is what an experienced operator already has in their hands and is arranged for a device nobody uses. Tamil 99 is the standard, is designed for the language, and asks for a few weeks.

These lessons teach Tamil 99. If your workplace runs on something else, that is the skill being asked for and no amount of being technically right changes it — but the standard is the one that travels.