The chapter explains how medial wāw can become alif, appear through a ī-like passive outcome, disappear under contraction, or remain in a different pattern.
Underlying form/rootSurface formMain reason
خَوِفَخَافَWeak-letter substitution to alif
Passive basisخِيفَPassive vocalisation and weak-letter change
يَخَافُلَمْ يَخَفْJussive contraction
خ و ف + fāʿilخَائِفٌHamzah substitution in active participle
A proper derivational explanation identifies the starting form, governing rule and outcome; naming the final form alone is insufficient.