8. Qāʿidat yaqūlu wa yabīʿu

If:

• before a yāʾ or wāw there is a sākin

Then:

• swap the ḥarakāt of the و or ي with the sukūn before it.

Example:

If:

• the wāw or yāʾ has a fatḥah
• before the yāʾ or wāw there is a sākin

Then:

• change the wāw or yāʾ to an alif.

Example:

The conditions for this change to take place are that the wāw and yāʾ do not occur:

1. In the fāʾ kalimah, e.g. تَوَعَّدَ, تَوَفَّى and تَيَسَّرَ
2. In the ʿayn lafīf¹, e.g. طَوَى and حَيِيَ
3. Before an extraneous madd, e.g. طَوِيْلٌ, غَيُوْرٌ and غَيَابَةٌ
4. In colours or defects, e.g. عَوِرَ and صَيِدَ

If:

• after an alif, wāw or yāʾ there is a sākin

Then:

• drop the alif, wāw or yāʾ.

• Give the letter before:

  • a ḍammah if it is a wāw
  • a kasrah if it is a yāʾ
  • a fatḥah if it is an alif.

Example:

Footnotes

1. When two ḥarf ʿillah occur in one verb. ↩