泰米爾文
In his "Tonnūḷ Viḷakkam", he differentiated between elongated and shortened vowel sounds in the Tamil script. For instance, 'எ' used to be written for both 'e' and 'é' before Veeramamunivar who introduced 'ஏ'. He brought about எ, ஏ, ஒ and ஓ.