الأفعال المعتلة — Weak Verbs
Arabic verbs are divided into sound (ṣaḥīḥ) verbs — where all three root letters are strong consonants — and weak (muʿtall) verbs — where one root letter is a ḥarf ʿillah (letter of weakness): و (wāw) or ي (yāʾ).
Weak letters are unstable: they change shape, disappear, or transform depending on surrounding vowels, causing these verbs to conjugate differently from sound verbs.
Three Types of Weak Verbs
| Position | Arabic Name | Alternative Name | Description | Example |
|---|---|---|---|---|
| Weak 1st radical | مُعْتَلّ الفَاء | مِثَال | First root letter is wāw or yāʾ | وَجَدَ (w-j-d), وَعَدَ (w-ʿ-d) |
| Weak 2nd radical | مُعْتَلّ العَيْن | أَجْوَف | Middle root letter is wāw or yāʾ | قَالَ (q-w-l), سَارَ (s-y-r) |
| Weak 3rd radical | مُعْتَلّ اللَّام | نَاقِص | Third root letter is wāw or yāʾ | دَعَا (d-ʿ-w), رَمَى (r-m-y) |
The Terminology
Both naming systems are valid. The فَاء / عَيْن / لَام system refers to the traditional morphological paradigm فَعَلَ, where: - فَاء الفِعْل = first radical - عَيْن الفِعْل = second radical - لَام الفِعْل = third radical
Learning Terminology
You do not need to memorise the names. Understanding which position is weak and how it affects conjugation is what matters. The names will be absorbed through repeated exposure.
Nāqiṣ Verbs — Weak Third Radical
The most commonly encountered weak type in the Quran is the nāqiṣ verb (weak third radical). The final wāw or yāʾ behaves unpredictably:
Example: يَدْعُو (to call) — Root: د-ع-و
In theory the muḍāriʿ would be يَدْعُوُ but: 1. The wāw (weak letter) becomes unstable with the ḍamma after it 2. The final ḍamma is suppressed → يَدْعُو
The final wāw in يَدْعُو is the root letter — not a pronoun. Therefore, no alif al-fāriqah is written.
However, in the plural: - يَدْعُونَ (they call) — the wāw here is wāw al-jamāʿah (pronoun) + nūn - Majzūm: لَا يَدْعُوا — nūn dropped; alif al-fāriqah added after the pronoun wāw
Critical Distinction
In nāqiṣ verbs, two different wāws can appear close together — one from the root, one as a pronoun. Knowing which is which requires understanding both the root letters and the pronoun system thoroughly.
Why This Matters for Quran Reading
Many Quranic verbs are weak verbs. The ability to correctly identify: - which letters are root letters - which letters are pronouns - which letters are signs of iʿrāb
...is essential for accurate grammatical analysis of Quranic text.
Miṯāl Wāwī — The Wāw-to-Tāʾ Transformation
In miṯāl wāwī verbs (initial-wāw verbs), the initial wāw can transform into a tāʾ in certain derived forms — not only in Form VIII but also in some base-form derivatives. This produces unexpected spelling patterns:
| Derived Word | From Root | Notes |
|---|---|---|
| تَقِيّ (taqī = pious person) | و-ق-ي (waqā) | Ism fāʿil should be وَاقٍ but becomes تَقِيّ via wāw→tāʾ |
| تُرَاث (turāth = inherited wealth) | و-ر-ث (wariṯa) | Wāw became tāʾ; "as if born into the family" |
| تُخمَة (tukhma = indigestion) | و-خ-م (wakhama) | Wāw became tāʾ |
| تَقوَى (taqwā = piety) | و-ق-ي | Wāw (1st radical) became tāʾ in the maṣdar |
The pattern: whenever a miṯāl wāwī's initial wāw undergoes substitution to tāʾ, even outside of Form VIII, the resulting word may carry this tāʾ as a permanent feature.
Ajwaf Verbs — Ism Fāʿil and Plural Pattern
Ism Fāʿil: Wāw/Yāʾ Converts to Hamza
In ajwaf (hollow) verbs, when making the ism fāʿil on the pattern فَاعِل, the weak middle radical (wāw or yāʾ) converts to hamza:
| Verb | Root | Ism Fāʿil | What Happened |
|---|---|---|---|
| قَامَ (to stand/carry out) | ق-و-م | قَائِم | middle wāw → hamza |
| زَارَ (to visit) | ز-و-ر | زَائِر | middle wāw → hamza |
| سَارَ (to travel) | س-و-ر | سَائِر | middle wāw → hamza |
Plural Pattern: Hamza Reverts to Original Radical
When making the plural on the pattern فَعَل (faʿal), the hamza reverts to the original wāw/yāʾ:
| Ism Fāʿil | Plural | Explanation |
|---|---|---|
| قَائِم | قَوم | hamza → original wāw (from قَامَ) |
| زَائِر | زُوَّار | hamza → original wāw |
This is why قَوم contains a wāw — it is the original middle radical of قَامَ returning in the plural.
Ajwaf Verbs — Mutaḥarrik Pronouns and the Dropping of the Weak Letter
When conjugating an ajwaf verb and the pronoun suffix becomes mutaḥarrik (carries a ḥarakah), the third radical takes a sukūn. This causes iltiqāʾ al-sākinayn (two sukūns meeting) because the middle weak letter (alif/wāw/yāʾ) is already sākin — so the weak letter is dropped.
After dropping, the first radical's vowel changes:
| Dropped weak letter | First radical vowel | Example |
|---|---|---|
| wāw | → ḍamma | قَالَ → قُلنَا (from ق-و-ل) |
| yāʾ | → kasra | نَامَ → نِمنَا (from ن-و-م, bāb: yanam) |
مَات — Two Bābs, Two Mutaḥarrik Forms
مَات (to die, root م-و-ت) belongs to two bābs:
| Bāb | Muḍāriʿ | Mutaḥarrik form |
|---|---|---|
| Bāb au | يَمُوتُ | مُتُّم (ḍamma on mīm — wāw dropped) |
| Bāb ai | يَمَاتُ | مِتُّم (kasra on mīm) |
Both مُتُّم and مِتُّم occur in the Quran. In the muḍāriʿ, only يَمُوتُ is used in the Quran (never يَمَاتُ).
The mītā / mayyit ism fāʿil follows the same weak-letter pattern — see مُتَوَارَة for related form pairs.
Session References
- Surah Al-Hujuraat Session 2: Introduction to three types of weak verbs; nāqiṣ verb explained via the example يَدْعُو (d-ʿ-w); connection to alif al-fāriqah.
- Surah Al-Hujuraat Session 4: Miṯāl wāwī — wāw-to-tāʾ transformation in base-form derivatives (تَقوَى، تُرَاث، تُخمَة); derivation of تَقِيّ from وَقَى.
- Surah Al-Hujuraat Session 12: Ajwaf ism fāʿil — wāw/yāʾ converts to hamza; plural reversion pattern; demonstrated with قَائِم → قَوم.
- Selections from the Glorious Quran Session 20: Ajwaf mutaḥarrik pronoun rule — weak letter drops; first radical takes ḍamma (wāw dropped) or kasra (yāʾ dropped); demonstrated with مَات in two bābs.