Derived Forms II–X add recognizable consonants and vowels around a root, but those templates do not neutralize weak و and ي. Sometimes the extra consonants protect the weak radical: Form III قَاوَمَ / يُقَاوِمُ keeps root ق-و-م visibly as و. Sometimes the weak radical contracts into a long vowel: Form VII اِنْقَادَ / يَنْقَادُ from ق-و-د. A final weak radical can appear as ى, ي, or hamza across one principal-part set: Form X اِسْتَدْعَى / يَسْتَدْعِي / اِسْتِدْعَاء from د-ع-و.
There is therefore no operation called “conjugate a weak derived verb” that works without a lexical entry. Identify the Form, the weak radical's position, and verified principal parts first. Then ordinary tense, mood, and agreement endings apply to the resulting stem. The following map compares attested families; the next pages give Form IV, VIII, and X their own detailed paradigms.
A compact map of attested outcomes
| Form and weak class | Verified principal parts | What the weak radical does |
|---|---|---|
| II, final-weak | سَمَّى / يُسَمِّي / تَسْمِيَة | ى in perfect, ي in imperfect, and ي + ة in maṣdar |
| III, middle-wāw | قَاوَمَ / يُقَاوِمُ / مُقَاوَمَة | wāw remains consonantal between long ā and a vowel |
| III, final-weak | نَادَى / يُنَادِي / مُنَادَاة | final ى alternates with ي; maṣdar ends in اة |
| V, final-weak | تَوَلَّى / يَتَوَلَّى / تَوَلٍّ | finite ى; indefinite defective maṣdar can lose final ي |
| VI, final-weak | تَسَاوَى / يَتَسَاوَى / تَسَاوٍ | finite ى; defective maṣdar تساوٍ |
| VII, hollow | اِنْقَادَ / يَنْقَادُ / اِنْقِيَاد | middle radical contracts in finite stems but appears in maṣdar spelling |
| VIII, initial-wāw | اِتَّصَلَ / يَتَّصِلُ / اِتِّصَال | root و assimilates to the Form-VIII ت |
| X, final-weak | اِسْتَدْعَى / يَسْتَدْعِي / اِسْتِدْعَاء | ى ~ ي ~ اء across principal parts |
This table is a reading map, not a promise that every root has a verb in every Form. Derived Forms are lexical: سمّى is an established Form-II verb meaning “name,” but Arabic does not license a speaker to put any weak root into Form II and calculate a new word.
Forms II and V: gemination may protect the middle but not the end
Form II doubles the middle radical. With final-weak سَمَّى / يُسَمِّي / تَسْمِيَة, root س-م-و, the doubled مّ is stable while the third radical alternates. The perfect has final alif maqṣūra ى; the imperfect has ي; the maṣdar uses ـية. Consonantal perfect suffixes do not all produce one generic “shortening”: the weak radical surfaces as -ay- in سَمَّيْتُ “I named,” سَمَّيْنَا “we named,” and سَمَّيْنَ “they (f.) named,” but it is absent before the third-person feminine-singular suffix in سَمَّتْ “she named.”
سمت اللجنة المبادرة باسم الطبيبة المؤسسة.
sammati l-lajnatu l-mubādarata bismi ṭ-ṭabībati l-muʾassisa.
The committee named the initiative after the founding physician.
لن تسمي الباحثتان أي مشارك قبل الحصول على موافقته.
lan tusammiya l-bāḥithatāni ʾayya mushārikin qabla l-ḥuṣūli ʿalā muwāfaqatih.
The two women researchers will not name any participant before obtaining consent. (Subjunctive after لن; neutral VSO.)
الباحثتان لم تسميا المشاركين في النسخة المنشورة.
al-bāḥithatāni lam tusammiyā l-mushārikīna fī n-nuskhati l-manshūra.
The two women researchers did not name the participants in the published version. (Subject-first dual agreement.)
Form V often relates lexically to Form II, but its meaning is not mechanically “reflexive Form II.” تَوَلَّى / يَتَوَلَّى / تَوَلٍّ, root و-ل-ي, means “assume; take charge of” and normally takes a direct object. Its perfect preserves initial root و because it is no longer exposed at the beginning of the stem; its final weak radical still controls the ending.
تولت المهندستان إدارة المشروع بعد تقاعد المدير السابق.
tawallati l-muhandisatāni ʾidārata l-mashrūʿi baʿda taqāʿudi l-mudīri s-sābiq.
The two women engineers took charge of the project after the previous director retired. (Neutral VSO.)
Forms III and VI: one root can preserve wāw or end defectively
In Form III قَاوَمَ / يُقَاوِمُ / مُقَاوَمَة, root ق-و-م, the middle wāw is pronounced as a consonant: qāwama, not a contracted hollow stem. This contrasts with Form IV أَقَامَ / يُقِيمُ, built from the same root but with a different template. The Form is therefore part of the explanation, not decoration.
قاوم السكان القرار بالوسائل القانونية المتاحة.
qāwama s-sukkānu l-qarāra bil-wasāʾili l-qānūniyyati l-mutāḥa.
The residents opposed the decision through the available legal means. (Formal.)
Final-weak Form III نَادَى / يُنَادِي / مُنَادَاة, root ن-د-و, instead alternates ى ~ ي, with اة in the maṣdar. Form VI تَسَاوَى / يَتَسَاوَى / تَسَاوٍ, root س-و-ي, keeps its final-weak behavior and gives a defective maṣdar.
نادت النقابة بتحسين شروط السلامة في المصانع.
nādati n-niqābatu bitaḥsīni shurūṭi s-salāmati fī l-maṣāniʿ.
The union called for improving safety conditions in factories. (Formal; نادى بـ ‘call for.’)
تساوت النتيجتان بعد الجولة الأخيرة، ولن تتساويا إذا تغيرت القواعد.
tasāwati n-natījatāni baʿda l-jawlati l-ʾakhīrati, wa-lan tatasāwayā ʾidhā taghayyarati l-qawāʿid.
The two results became equal after the final round, and they will not be equal if the rules change.
English call for and be equal do not reveal either Form or preposition. Learn نادى بـ and تساوى مع where that second participant is expressed.
Form VII: a hollow finite stem and a visible maṣdar family
Form VII اِنْقَادَ / يَنْقَادُ / اِنْقِيَاد, root ق-و-د, means “submit; be led; comply” and commonly takes لـ. The long vowel of انقاد / ينقاد shortens when the stem loses its ending in the singular jussive: لَمْ يَنْقَدْ. It also shortens before consonantal perfect suffixes: اِنْقَدْتُ.
انقاد السائقان لتعليمات فريق الإنقاذ فور سماع الإنذار.
inqāda s-sāʾiqāni litaʿlīmāti farīqi l-ʾinqādhi fawra samāʿi l-ʾindhār.
The two drivers complied with the rescue team's instructions as soon as they heard the alarm. (Neutral VSO.)
لم ينقد الفريق للضغط، بل طلب مراجعة مستقلة.
lam yanqadi l-farīqu liḍ-ḍaghṭi, bal ṭalaba murājaʿatan mustaqilla.
The team did not yield to pressure; instead, it requested an independent review. (Jussive short stem.)
Do not extrapolate that every Form VII verb is passive or every hollow Form VII verb uses this exact meaning. انقاد is a verified lexeme; the pattern does not manufacture vocabulary.
Forms VIII and X: different prefixes, different weak interactions
Form VIII places ت after the first radical. With initial-wāw و-ص-ل, the root wāw assimilates to that ت, producing اِتَّصَلَ / يَتَّصِلُ / اِتِّصَال “contact; be connected,” not an invented form preserving both و and ت. Form X places استـ before the root, so final-weak اِسْتَدْعَى / يَسْتَدْعِي / اِسْتِدْعَاء follows another surface family.
اتصلت الطبيبتان بالمختبر، ثم استدعتا فنيين إضافيين.
ittaṣalati ṭ-ṭabībatāni bil-mukhtabari, thumma stadʿatā fanniyyayni ʾiḍāfiyyayn.
The two doctors contacted the laboratory and then summoned two additional technicians. (Neutral VSO, then dual agreement.)
لم يتصل المدير بالمورد، ولم يستدع ممثليه إلى الاجتماع.
lam yattaṣili l-mudīru bil-muwarridi, wa-lam yastadʿi mumaththilayhi ʾilā l-ijtimāʿ.
The director did not contact the supplier or summon its two representatives to the meeting. (Two different jussive outcomes.)
Form VIII doubles ت here; Form X final-weak jussive deletes final ي. The detailed Form VIII weak-root guide and Form X weak-verb guide show why those changes cannot be merged into one rule.
Common Mistakes
Applying Form-I initial-wāw loss to every derived Form
❌ تلى المهندستان إدارة المشروع.
Incorrect—the established Form-V verb is تولى; its initial root و remains inside the prefixed stem.
✅ تولت المهندستان إدارة المختبر.
tawallati l-muhandisatāni ʾidārata l-mukhtabar.
The two women engineers took charge of the laboratory.
Contracting a Form-III wāw as though it were Form IV
❌ قام السكان القرار بالوسائل القانونية.
Incorrect—قاوم ‘oppose’ is Form III and retains و; قام is a different Form-I verb.
✅ قاوم السكان القرار بالوسائل القانونية.
qāwama s-sukkānu l-qarāra bil-wasāʾili l-qānūniyya.
The residents opposed the decision through legal means.
Keeping a long vowel in a hollow jussive
❌ لم ينقاد الفريق للضغط.
Incorrect in careful MSA—the singular hollow jussive shortens: لم ينقد.
✅ لم ينقد الفريق للضغط.
lam yanqadi l-farīqu liḍ-ḍaghṭ.
The team did not yield to pressure.
Inventing one maṣdar ending for all final-weak verbs
❌ ناقشت اللجنة منادية النقابة بالإصلاح.
Incorrect lexical form—the maṣdar of نادى is مناداة, not an invented منادية.
✅ ناقشت اللجنة مناداة النقابة بالإصلاح.
nāqashati l-lajnatu munādāta n-niqābati bil-ʾiṣlāḥ.
The committee discussed the union's call for reform.
Giving a neutral VSO clause full dual agreement
❌ تولتا المهندستان إدارة المشروع.
Incorrect in neutral formal VSO—before an overt dual subject, use singular feminine تولت.
✅ تولت المهندستان إدارة المشروع.
tawallati l-muhandisatāni ʾidārata l-mashrūʿ.
The two women engineers took charge of the project.
Key Takeaways
- Weak radicals interact with each derived-form template differently; root position alone does not predict the surface form.
- Learn only attested verbs, with perfect, imperfect, maṣdar, Form, root, and complements.
- The Form-III wāw of قاوم remains consonantal, while hollow انقاد contracts and shortens in the jussive.
- Final-weak sets such as سمّى / يسمّي / تسمية and استدعى / يستدعي / استدعاء must be stored as principal-part families.
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Start learning Arabic →Related Topics
- Participles of Weak VerbsB1 — Form and decline weak-verb participles such as قائل، مبيع، and داعٍ without regularizing their weak radicals or noun endings.
- Verbal Nouns of Weak VerbsB1 — Learn lexical Form I weak maṣdars and the recurring weak-root adjustments in derived Forms, including real tāʾ marbūṭa patterns.
- Form IV Hollow VerbsB1 — Conjugate أقام and related Form IV hollow verbs through their long and short stems, moods, command, passive, and nominal forms.
- Form VIII with Weak RootsB1 — Distinguish initial-wāw assimilation, hollow contraction, and final-weak deletion in verified Form VIII verbs such as اتصل، اختار، and اتقى.
- Form X Weak VerbsB1 — Conjugate final-weak, hollow, and initial-wāw Form X verbs through verified families such as استدعى، استقام، استطاع، and استوعب.
- The Arabic Verb SystemA1 — See how Arabic verb stems, agreement, mood, voice, and derived Forms work together in complete sentences.