Venpa (வெண்பா in Tamil) is a form of classical tamil poetry. Classical Tamil poetry has been classifed based upon the rules of metric prosody. Such rules form a context-free grammar. Every Venpa consists between two to twelve lines.

Popular books written in Venpa style

1. All 1330 couplets from Tirukkural, composed by Tiruvalluvar are examples of Venpa. Tirukkural comes under a sub-category of Venpa called Kural Venpa, wherein each Kural has only two lines.
2. Nala venpa ¹ is another classical work written in venpa style.
3. Niti venpa ² is another venpa style book that preaches values.

Basic units of meter in classical Tamil poetry

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 sIr or cheer is a type of metrical foot that roughly corresponds to an iamb. Thalai is the juxtaposition of iambic patterns.

Grammar for meter in Venpa

A set of well defined metric rules define the grammar for Venpa. Such rules have been proved to form a Context-free grammar.

One set of rules constrains the duration of sound for each word or cheer, while another set of rules defines the rules for the possible sounds at the beginning of a word that follows a given sound at the end of the preceding word. Any Venpa should conform to both these sets of rules.

Following is the set of production rules corresponding to the first set of rules.

<VENPAA> → <ADI>{1-11} <EETRADI>
<ADI> → <CHEER> <CHEER> <CHEER> <CHEER>
<EETRADI> → <CHEER> <CHEER> <EETRU CHEER>
<CHEER> → <EERASAI> | <MOOVASAI>
<EETRU CHEER> → <NAAL> | <MALAR> | <KAASU> | <PIRAPPU>
<EERASAI> → <THEMAA> | <PULIMAA> | <KARUVILAM> | <KOOVILAM>
<MOOVASAI> → <THEMAANGAAI> | <PULIMAANGAAI> | <KOOVILANGAAI> | <KARUVILANGAAI>
<THEMAA> → <NER> <NER>
<PULIMAA> → <NIRAI> <NER>
<KARUVILAM> → <NIRAI> <NIRAI>
<KOOVILAM> → <NER> <NIRAI>
<THEMAANGAAI> → <THEMAA> <NER>
<PULIMAANGAAI> → <PULIMAA> <NER>
<KARUVILANGAAI> → <KARUVILAM> <NER>
<KOOVILANGAAI> → <KOOVILAM> <NER>
<NAAL> → <NER>
<MALAR> → <NIRAI>
<KAASU> → <NER> <NER>
<PIRAPPU> → <NIRAI> <NER>
<NER> → <KURIL> | <NEDIL> | <NER> <OTRU>
<NIRAI> → <KURIL> <KURIL> | <KURIL> <NEDIL> | <NIRAI> <OTRU>
<KURIL> → {VOWELS OR COMPOUNDS WITH A SHORT SOUND}
<NEDIL> → {VOWELS OR COMPOUNDS WITH A LONG SOUND}
<OTRU> → {CONSONANTS, WHICH HAVE AN EXTREMELY SHORT SOUND}

1. {1-11} is not a standard BNF notation but a widely accepted EBNF notation indicating   
repetition of number of times specified in the range.
2. The grammar has some redundant productions that have been retained so as to preserve 
the semantics as described originally in Tamil grammar.

Following is the set of production rules corresponding to the second set of rules.

<VENPAA>   → <X> | <Y>
<X>	 → <THEMAA> <Y>
<X>	 → <KOOVILAM> <X>
<Y>	 → <PULIMAA> <Y>
<Y>	 → <KARUVILAM> <X>
<X>	 → <NAAL> | <KAASU>
<Y>	 → <MALAR> | <PIRAPPU>

[If the above rules are conformed to, the thalai is said to be Iyarcheer vendalai]

<X>	 → <THEMAANGAAI> <X>
<X>	 → <KOOVILAANGAAI> <X>
<Y>	 → <PULIMAANGAAI> <X>
<Y>	 → <KARUVILANGAAI> <X>

[If the above rules are conformed to, the thalai is said to be Vencheer vendalai]

Example

Following is a couplet from Tirukkural:

உடுக்கை இழந்தவன் கைபோல ஆங்கே
இடுக்கண் களைவதாம் நட்பு.

(a translation by G U Pope)
"As hand of him whose vesture slips away,
Friendship at once the coming grief will stay.
(True) friendship hastens to the rescue of the afflicted (as readily) as the hand of one whose
garment is loosened (before an assembly)."

External links

• Nala Venpa (pdf version)
• Niti Venpa (TSCII encoding)
• Rules for Venpa
• Context Free Grammar for Natural Language Constructs. An implementation for Venpa Class of Tamil Poetry (2003, research paper)