Here are the eight types of ettuthogai:
1. Venpa: A simple meter with four lines, each containing 8 syllables.
2. Kali: A more complex meter with four lines, each containing 12 syllables.
3. Aasiriyam: A four-line meter with 16 syllables in each line.
4. Vañci: A four-line meter with 20 syllables per line.
5. Talaiyankam: A four-line meter with 24 syllables per line.
6. Paripadal: A four-line meter with 28 syllables per line.
7. Kattalai: A four-line meter with 32 syllables per line.
8. Siṛppa: A four-line meter with 36 syllables per line.
These meters have strict rules regarding the arrangement of syllables and the placement of specific sounds, contributing to the beauty and musicality of Tamil poetry.