Venpa (வெண்பா in Tamil) is a form of classical Tamil poetry. Classical Tamil poetry has been classified based upon the rules of metric prosody. Such rules form a context-free grammar. Every Venpa consists of between two to twelve lines.
Vowels and consonant-vowel compounds in Tamil alphabet have been classified into ones with short sounds (kuril) and the ones with long sounds (nedil). A sequence of one or more of these units optionally followed by a consonant can form a ner asai (the Tamil word asai roughly corresponds to syllable) or a nirai asai depending on the duration of pronunciation. Ner and Nirai are the basic units of meter in Tamil prosody. A siir or cheer is a type of metrical foot that roughly corresponds to an iamb. Thalai is the juxtaposition of iambic patterns.