These five rules demonstrate three distinct operations:
Word / formMeaning / explanation
Elisionيَوْعِدُ → يَعِدُ: wāw disappears.
Substitutionمِوْزَانٌ → مِيزَانٌ: wāw becomes yāʾ.
Assimilationاِوْتَقَدَ → اِتَّقَدَ: wāw becomes tāʾ, which merges with another tāʾ.
A sound analysis tracks the original radicals, vowel pattern and added consonants of the verbal form together.