Ai: The Second Step of the Ladder

Ai is the twelfth letter of the varnamala and the second of the combination vowels. In the grammarians' scheme it stands one degree beyond e: where e is the first strengthening of i, ai is the second, produced by the process the tradition calls vrddhi. Like all four sandhyakshara it is always long and always makes its syllable heavy in metre, and like them it has no short counterpart in the series. Its vowel sign is a pair of slanted strokes above the headline, distinguished from the single stroke of e only by the doubling, which is one of several places in Devanagari where a longer or stronger sound is written as the shorter sign with something added. The letter is common in derived vocabulary precisely because the second strengthening grade is used to form a large class of derivatives, including patronymics, adjectives of relation and abstract nouns, so a word beginning with ai is very often a formation built on a root whose own vowel is i or e.

Recognising that is part of reading Sanskrit efficiently, since the strengthened vowel signals the derivation before the rest of the word is parsed. The independent letter is used where a word opens with the vowel or where the vowel follows another across a join, and the rules by which it arises are stated in the same body of grammar that produces e.