بَنَى “build” is a Form-I verb from root ب-ن-ي. It is final-weak, or defective: its last radical appears as ى in بنى, as ي in يبني and بنيتُ, and disappears from singular لم يبنِ and اِبْنِ. These alternations matter in the most ordinary uses of the verb, so a learner needs more than the dictionary headword.
The core syntax is equally useful. بنى بيتًا describes constructing an object, بنى لأسرتِه بيتًا adds the person for whom it was built, and بنى رأيَه على الأدلة means “base his opinion on the evidence.” English build on covers both literal and abstract relations; Arabic على does too, but only when there is a supporting base. The beneficiary is instead expressed with لـ.
For the general morphology behind يبني، لم يبنِ، ابنِ, see the final-weak mood guide; the present page adds this verb's lexical government and passive behavior.
Lookup card: بَنَى — يَبْنِي
| Part | Verified form | Use |
|---|---|---|
| root and Form | ب-ن-ي، Form I | final-weak in yāʾ |
| perfect, 3 m.sg. | بَنَى | he built |
| imperfect, 3 m.sg. | يَبْنِي | he builds / is building |
| imperative, 2 m.sg. | اِبْنِ | build! |
| verbal noun | بِنَاءٌ | building; construction |
| active participle | بَانٍ؛ الْبَانِي | builder; one building |
| passive participle | مَبْنِيٌّ | built; based; indeclinable (grammar) |
| passive | بُنِيَ — يُبْنَى | was / is built |
The active participle follows the defective-noun pattern: بانٍ loses final yāʾ when indefinite nominative or genitive, but الباني and construct باني الجسر retain it. In contemporary prose, the finite verb and passive participle are much more frequent than bare بانٍ. مبني also has a specialized grammatical meaning, “indeclinable,” as in اسم مبني, which is related metaphorically to being fixed but should be learned as a technical term (academic).
بنت الشركة مدرسة جديدة في القرية.
banati sh-sharikatu madrasatan jadīdatan fī l-qarya.
The company built a new school in the village. (Formal neutral.)
يبني الفريق نموذجا أوليا لاختبار الفكرة.
yabnī l-farīqu namūdhajan ʾawwaliyya li-khtibāri l-fikra.
The team is building a prototype to test the idea. (Formal/technical.)
How the final yāʾ changes
Before consonant-initial perfect suffixes, yāʾ surfaces: بنيتُ، بنيتَ، بنينا. The feminine singular is contracted to بَنَتْ, and masculine plural is بَنَوْا. In the imperfect, yāʾ remains in the indicative and the singular subjunctive, but disappears in the singular jussive.
| Environment | Form | Stem behavior |
|---|---|---|
| هو, perfect | بَنَى | final radical written as ى |
| أنا / نحن, perfect | بَنَيْتُ / بَنَيْنَا | yāʾ surfaces before suffix |
| هي / هم, perfect | بَنَتْ / بَنَوْا | contracted feminine; yāʾ becomes glide w before وا |
| indicative | يَبْنِي | final yāʾ retained |
| after لَنْ | لَنْ يَبْنِيَ | yāʾ retained before subjunctive fatḥa |
| after لَمْ | لَمْ يَبْنِ | final yāʾ deleted |
بنينا النظام على بيانات من ثلاث سنوات.
banaynā n-niẓāma ʿalā bayānātin min thalāthi sanawāt.
We built the system on data from three years. (Formal/technical.)
لن يبني المقاول الطابق الأخير قبل صدور الترخيص.
lan yabniya l-muqāwilu ṭ-ṭābiqa l-ʾakhīra qabla ṣudūri t-tarkhīṣ.
The contractor will not build the top floor before the permit is issued. (Formal; subjunctive.)
لم يبن الباحث استنتاجه على عينة كافية.
lam yabni l-bāḥithu stintājahu ʿalā ʿayyinatin kāfiya.
The researcher did not base his conclusion on a sufficient sample. (Academic; singular jussive.)
The masculine-singular command is اِبْنِ; commands to other addressees are اِبْنِي، اِبْنِيَا، اِبْنُوا، اِبْنِينَ. The initial alif is hamzat al-waṣl, pronounced only when speech begins with the imperative.
ابن خطتك على الموارد المتاحة، لا على الوعود.
ibni khuṭṭataka ʿalā l-mawāridi l-mutāḥati, lā ʿalā l-wuʿūd.
Build your plan on the available resources, not on promises. (Formal advice to one man.)
Ranked meanings and valency
1. Construct a physical object
The thing built is a direct object: بنى البيتَ، بنى الجسرَ، بنى المصنعَ. The material can follow من, the location can follow في or على, and the person benefiting from the construction can follow لـ.
بنى السكان الجدار من الحجر المحلي.
banā s-sukkānu l-jidāra mina l-ḥajari l-maḥallī.
The residents built the wall from local stone. (Formal neutral.)
بنى الزوجان لأطفالهما بيتا قرب المدرسة.
banā z-zawjāni liʾaṭfālihimā baytan qurba l-madrasa.
The couple built their children a house near the school. (Formal neutral.)
The beneficiary phrase is movable: بنى لأطفاله بيتًا and بنى بيتًا لأطفاله are both grammatical. The earlier phrase tends to be more topical or contrastive. This is not the same function as على, which identifies a base or foundation.
2. Build, develop, or establish an abstract structure
Arabic extends بنى naturally to systems, institutions, relationships, arguments, capacities, and careers. This is standard formal MSA, not a forced English calque. The object still behaves like an ordinary direct object.
بنت المؤسسة شبكة من العيادات الريفية.
banati l-muʾassasatu shabakatan mina l-ʿiyādāti r-rīfiyya.
The organization built a network of rural clinics. (Formal.)
يحتاج القائد إلى وقت لبناء الثقة داخل الفريق.
yaḥtāju l-qāʾidu ʾilā waqtin libināʾi th-thiqati dākhila l-farīq.
A leader needs time to build trust within the team. (Formal neutral.)
3. Base a claim or decision on something
The frame بنى X على Y presents Y as the supporting foundation for X. Frequent objects include رأي، قرار، حجة، استنتاج، خطة. In the passive, بُنِيَ X على Y means “X was based on Y.” The fixed connector بناءً على means “based on / pursuant to” (formal/administrative) and contains the verbal noun in the accusative.
بنت اللجنة توصياتها على نتائج التحقيق.
banati l-lajnatu tawṣiyātihā ʿalā natāʾiji t-taḥqīq.
The committee based its recommendations on the investigation's findings. (Formal.)
اتخذ القرار بناء على تقييم مستقل للمخاطر.
uttukhidha l-qarāru bināʾan ʿalā taqyīmin mustaqillin lil-makhāṭir.
The decision was made on the basis of an independent risk assessment. (Formal/administrative.)
Passive and participles
The passive is common because formal prose often foregrounds a building, system, or argument rather than its creator. Perfect بُنِيَ keeps yāʾ; imperfect يُبْنَى ends in alif maqṣūra. The passive participle مَبْنِيّ can describe both literal construction and an abstract basis.
بني الجسر في أقل من عامين.
buniya l-jisru fī ʾaqalla min ʿāmayn.
The bridge was built in less than two years. (Formal passive.)
تبنى الموازنة الجديدة على تقديرات أكثر تحفظا.
tubnā l-muwāzanatu l-jadīdatu ʿalā taqdīrātin ʾakthara taḥaffuẓan.
The new budget is based on more conservative estimates. (Formal/economic.)
هذا الادعاء مبني على افتراض غير مثبت.
hādhā l-iddiʿāʾu mabniyyun ʿalā ftirāḍin ghayri muthbat.
This claim is based on an unproven assumption. (Academic.)
High-frequency collocations
| Collocation | Meaning and register |
|---|---|
| بَنَى بَيْتًا / جِسْرًا | build a house / bridge (neutral) |
| بَنَى نِظَامًا | build a system (formal/technical) |
| بَنَى الثِّقَةَ | build trust (neutral/formal) |
| بَنَى رَأْيَهُ عَلَى | base his opinion on (formal) |
| بِنَاءً عَلَى الطَّلَبِ | at / based on the request (formal/administrative) |
| مَبْنِيٌّ عَلَى الْأَدِلَّةِ | evidence-based (formal/academic) |
Common Mistakes
Keeping yāʾ after لم
❌ لم يبني المقاول السور بعد.
Incorrect for the singular jussive—the final yāʾ is deleted after لم.
✅ لم يبن المقاول السور بعد.
lam yabni l-muqāwilu s-sūra baʿd.
The contractor has not built the wall yet.
Writing the imperative with final yāʾ
❌ ابني حجتك على مصادر موثوقة.
Incorrect when addressing one man—ابني is the feminine-singular command; the masculine-singular form is ابنِ.
✅ ابن حجتك على مصادر موثوقة.
ibni ḥujjataka ʿalā maṣādira mawthūqa.
Build your argument on reliable sources. (Addressed to one man.)
Using لـ for the evidential foundation
❌ بنى الباحث استنتاجه للبيانات الأولية.
Incorrect for ‘based his conclusion on’; the supporting evidence takes على, not لـ.
✅ بنى الباحث استنتاجه على البيانات الأولية.
banā l-bāḥithu stintājahu ʿalā l-bayānāti l-ʾawwaliyya.
The researcher based his conclusion on the preliminary data.
Treating مبني as only a physical adjective
❌ الرأي مبني من معلومات ناقصة.
Incorrect government for an abstract basis—مبني takes على when it means ‘based on.’
✅ الرأي مبني على معلومات ناقصة.
ar-raʾyu mabniyyun ʿalā maʿlūmātin nāqiṣa.
The opinion is based on incomplete information.
Key Takeaways
- بنى — يبني is final-weak in yāʾ; singular لم يبنِ and ابنِ delete that final yāʾ.
- The constructed thing is a direct object, a beneficiary takes لـ, and a foundation or evidential basis takes على.
- Abstract objects such as systems, trust, arguments, and careers combine naturally with بنى in formal MSA.
- The passive بُنِيَ — يُبْنَى and participle مبني على are frequent in technical and academic prose.
- بناءً على is a fixed formal connector meaning “based on” or “pursuant to.”
Related Topics
- دعا — callB2 — Conjugate the final-weak verb دعا and distinguish calling, inviting, advocating, praying, and naming through its core complement frames.
- أرسل — send with direct object plus إلى or لـB2 — Use أرسل with the thing or person sent, choose إلى or لـ for recipients, and recognize its active, passive, and communications forms.
- كان — beA2 — Reference the hollow verb كان across its full paradigm, copular and existential senses, predicate case, conditionals, and high-frequency collocations.