If:
Then:
Example:
| دُعِوَ | → | دُعِيَ |
| دُعِوَا | → | دُعِيَا |
| دَاعِوَانِ | → | دَاعِيَانِ |
| دَاعِوَةٌ | → | دَاعِيَةٌ |
Morphological rule: a ي in the lām position after a ḍammah converts to a و.
When wāw or yāʾ falls at the end of a word after an alif zāʾidah, it is converted to a hamzah.
When a wāw sits as the ʿayn kalimah of a maṣdar after a kasrah, or in a plural, it converts to a yāʾ if its verb takes the rules of taʿlīl.
When a wāw or yāʾ falls in the ʿayn position of an active participle whose verb is muʿtal, it converts to hamzah.
