Tawil

It comprises distichs (bayt) of two 'lines'—in Arabic usually written side by side, with a space dividing them, the first being called the sadr (صدر, literally "chest") and the other the ʿajuz (عجز, literally "belly"). Its basic form is as follows (the symbol – representing a long syllable, ⏑ representing a short syllable, and x representing a syllable that can be short or long):

| ᴗ – x | ᴗ – – – | ᴗ – x | ᴗ – ᴗ – | (2×)

This form can be exemplified through the traditional mnemonic Faʿūlun Mafāʿīlun Faʿūlun Mafāʿilun (فَعولُن مَفاعيلُن فَعولُن مَفاعِلُن).

The final syllable of every distich rhymes throughout the whole poem; a long poem might comprise a hundred distichs. In Classical verse, each distich is a complete syntactic unit.

Variations

The Encyclopaedia of Islam records three sub-types of ṭawīl hemistich, of which the second is the most common:

1. | ᴗ – x | ᴗ – – – | ᴗ – x | ᴗ – ᴗ – | * | ᴗ – x | ᴗ – – – | ᴗ – x | ᴗ – – – |
2. | ᴗ – x | ᴗ – – – | ᴗ – x | ᴗ – ᴗ – | * | ᴗ – x | ᴗ – – – | ᴗ – x | ᴗ – ᴗ – |
3. | ᴗ – x | ᴗ – – – | ᴗ – x | ᴗ – ᴗ – | * | ᴗ – x | ᴗ – – – | ᴗ – x | ᴗ – – |

In the rare cases where a poem requires rhyme at the end of each hemistich, the last foot of the first hemistich has the same pattern as the last foot of the second, to enable the rhyme.

In ancient poetry, the first unstressed syllable of the line is sometimes omitted, and the second foot of each hemistich can be | ᴗ – ᴗ – | instead of | ᴗ – – – |.