اِسْتَطَاعَ / يَسْتَطِيعُ is the most dependable formal-MSA verb for “be able to, can, manage to.” It is an irregular hollow Form-X verb from root ط-و-ع. Its long vowel alternates with a short stem: استطاع but استطعتُ, يستطيع but لم يستطعْ.
Unlike English modal can, استطاع is an ordinary conjugated verb: it has past and nonpast forms, agrees with its subject, can follow particles such as لم and لن, and usually introduces the enabled action with أن + subjunctive. That fuller syntax is one reason it is especially useful in formal writing.
The Form-X weak-verb page supplies the wider morphological comparison. This page concentrates on the exceptionally frequent lexical verb and its contrast with قدر.
Lookup card and principal parts
| Item | Verified form | Use |
|---|---|---|
| root and Form | ط-و-ع، Form X | irregular hollow derived verb |
| perfect | اِسْتَطَاعَ | he was able / managed |
| imperfect indicative | يَسْتَطِيعُ | he can / is able |
| imperative, 2 m.sg. | اِسْتَطِعْ | be able! / manage!; valid but pragmatically restricted |
| verbal noun | اِسْتِطَاعَةٌ | ability, capability |
| active participle | مُسْتَطِيعٌ | able, capable; less frequent than قادر in many adjective frames |
| passive | اُسْتُطِيعَ — يُسْتَطَاعُ | was/is possible to accomplish; mainly impersonal |
| passive participle | مُسْتَطَاعٌ | possible, feasible; common in قدر المستطاع |
The principal-parts chain is اِسْتَطَاعَ — يَسْتَطِيعُ — اِسْتَطِعْ — اِسْتِطَاعَةً. The initial alif bears hamzat al-waṣl, not hamzat al-qaṭʿ: it is written plain ا and loses its glottal onset after a preceding vowel in connected speech. The internal alternation is lexical; do not try to rebuild استطاع from the ordinary sound-root Form-X pattern alone.
استطاع الفريق إصلاح الخلل من دون إيقاف الخدمة.
istaṭāʿa l-farīqu ʾiṣlāḥa l-khalali min dūni ʾīqāfi l-khidma.
The team managed to fix the fault without stopping the service. (Formal technical register.)
يستطيع هذا الجهاز قياس التغيرات الصغيرة في الضغط.
yastaṭīʿu hādhā l-jihāzu qiyāsa t-taghayyurāti ṣ-ṣaghīrati fī ḍ-ḍaghṭ.
This device can measure small changes in pressure. (Formal technical register.)
The irregular hollow alternation
The long ā remains in perfect forms whose ending begins with a vowel: اِسْتَطَاعَ، اِسْتَطَاعَتْ، اِسْتَطَاعَا، اِسْتَطَاعُوا. Before consonant-initial suffixes it shortens: اِسْتَطَعْتُ، اِسْتَطَعْتَ، اِسْتَطَعْنَا، اِسْتَطَعْنَ.
The indicative يستطيعُ and singular subjunctive أن يستطيعَ retain long ī. The jussive deletes it: لم يستطعْ. In the five verbs, mood is expressed by nūn deletion rather than loss of the stem vowel: يستطيعون، لن يستطيعوا، لم يستطيعوا and تستطيعين، لن تستطيعي.
استطعنا نقل الاجتماع إلى قاعة أكبر في اللحظة الأخيرة.
istaṭaʿnā naqla l-ijtimāʿi ʾilā qāʿatin ʾakbara fī l-laḥẓati l-ʾakhīra.
We managed to move the meeting to a larger room at the last minute. (Formal neutral.)
لم يستطع النظام قراءة الملف لأنه كان تالفا.
lam yastaṭiʿi n-niẓāmu qirāʾata l-malaf liʾannahu kāna tālifan.
The system could not read the file because it was corrupted. (Formal; shortened jussive with a linking i.)
لن يستطيعوا إنهاء المراجعة قبل مساء الخميس.
lan yastaṭīʿū ʾinhāʾa l-murājaʿati qabla masāʾi l-khamīs.
They will not be able to finish the review before Thursday evening. (Formal; nūn is deleted after لن.)
The imperative استطع is morphologically valid, but “be able!” is rarely a useful command. It appears in challenges, exhortations, and formulas such as افعل ما استطعت “do what you can.” Ordinary requests use the command of the actual action or a phrase such as حاول أن “try to.”
Two core complement patterns
أن + imperfect subjunctive
The most transparent frame is استطاع أن يفعل. أن introduces a finite verb in the subjunctive, so person and number remain visible: استطعت أن أجدَ، استطاعت أن تجدَ، استطاعوا أن يجدوا. With plural or feminine-singular forms among the five verbs, subjunctive nūn deletion applies.
استطاعت الباحثة أن تفسر النتيجة من دون افتراض عامل جديد.
istaṭāʿati l-bāḥithatu ʾan tufassira n-natījata min dūni ftirāḍi ʿāmilin jadīd.
The researcher was able to explain the result without assuming a new factor. (Academic.)
هل تستطيع أن ترسل النسخة الموقعة قبل الظهر؟
hal tastaṭīʿu ʾan tursila n-nuskhata l-muwaqqaʿata qabla ẓ-ẓuhr?
Can you send the signed copy before noon? (Polite formal request.)
Unlike English can you...?, this question literally asks about ability, but it functions naturally as a polite request when the context makes the desired action clear.
Direct verbal noun or action noun
Formal Arabic also allows استطاع + direct object, especially a verbal noun: استطاع حلَّ المشكلة، استطاع الوصولَ، استطاع إقناعَ اللجنة. This compresses the clause and is common in reports. It does not require a preposition.
لم تستطع الشركة الوفاء بالتزاماتها خلال السنة الأولى.
lam tastaṭiʿi sh-sharikatu l-wafāʾa biltizāmātihā khilāla s-sanati l-ʾūlā.
The company was unable to meet its obligations during the first year. (Formal business register.)
يستطيع القارئ الوصول إلى الجداول من الفهرس مباشرة.
yastaṭīʿu l-qāriʾu l-wuṣūla ʾilā l-jadāwili mina l-fihrisi mubāshara.
The reader can access the tables directly from the index. (Formal.)
Ability, opportunity, and successful achievement
In the present, يستطيع usually states current capacity or practical possibility: يستطيع السباحة “he can swim.” In the affirmative past, استطاع often implies that the subject actually managed to complete the action, not merely that the capacity existed. To describe unrealized past ability explicitly, use كان يستطيع أن... and add the circumstance that prevented the action.
كان يستطيع أن يرفض العرض، لكنه قبله بعد تعديل الشروط.
kāna yastaṭīʿu ʾan yarfuḍa l-ʿarḍa, lakinnahu qabilahu baʿda taʿdīli sh-shurūṭ.
He could have refused the offer, but he accepted it after the terms were amended. (Formal; past capacity, not a claim that he refused.)
This is a discourse tendency, not an iron rule: context can make استطاع describe availability of capacity. Still, the contrast between كان يستطيع “was able/could” and استطاع “managed” is a useful production default.
استطاع and قدر
Both verbs can express ability. استطاع أن يفعل / استطاع فعلَ الشيء is the broad, unmarked formal choice and readily reports successful achievement. قَدَرَ على الشيء foregrounds power, mastery, or capacity over something and fixes the complement with على; قدر أن يفعل is also attested. In several dialects, unvocalized يقدر is the everyday equivalent of “can,” but that regional frequency should not be projected unchanged onto carefully edited MSA.
استطاع المهندسون تشغيل المضخة، لكنهم لم يقدروا على تثبيت الضغط.
istaṭāʿa l-muhandisūna tashghīla l-miḍakhkhati, lakinnahum lam yaqdirū ʿalā tathbīti ḍ-ḍaghṭ.
The engineers managed to start the pump, but they could not stabilize the pressure. (Formal; على marks the قدر frame.)
Passive, participles, and collocations
Impersonal passive يُستطاع occurs in formal phrases such as لا يستطاع إنكاره “it cannot be denied.” Passive participle مستطاع is most familiar in قدر المستطاع “as far as possible / to the extent possible.” Active مستطيع is valid, but adjective قادر على is often more idiomatic for a stable capability.
هذا أمر لا يستطاع حسمه من دون بيانات إضافية.
hādhā ʾamrun lā yustaṭāʿu ḥasmuhu min dūni bayānātin ʾiḍāfiyya.
This is a matter that cannot be settled without additional data. (Formal impersonal passive.)
| Collocation | Meaning and register |
|---|---|
| اِسْتَطَاعَ أَنْ يَفْعَلَ | be able/manage to do (neutral formal) |
| اِسْتَطَاعَ فِعْلَ الشَّيْءِ | manage the action (compact formal prose) |
| لَمْ يَسْتَطِعْ | could not / did not manage (neutral) |
| قَدْرَ الْمُسْتَطَاعِ | as much/as far as possible (formal) |
| فِي حُدُودِ الِاسْتِطَاعَةِ | within one's capacity (formal) |
| لَا يُسْتَطَاعُ | cannot be done (formal impersonal) |
Common Mistakes
Keeping the long vowel before first-person ـتُ
❌ استطاعت إنهاء المهمة أمس.
Incorrect for ‘I managed’—استطاعت means ‘she managed’; first person shortens to استطعت.
✅ استطعت إنهاء المهمة أمس.
istaṭaʿtu ʾinhāʾa l-muhimmati ʾams.
I managed to finish the task yesterday.
Keeping ي in the singular jussive
❌ لم يستطيع البرنامج فتح الملف.
Incorrect—the jussive after لم deletes the hollow stem's long yāʾ.
✅ لم يستطع البرنامج فتح الملف.
lam yastaṭiʿi l-barnāmaju fatḥa l-malaf.
The program could not open the file.
Omitting أن before a finite complement
❌ استطاعت أن تشرح النتيجة.
istaṭāʿat ʾan tashraḥu n-natīja
Incorrect reading—the finite complement is subjunctive tashraḥa after أن, not indicative tashraḥu.
✅ استطاعت أن تشرح النتيجة بوضوح.
istaṭāʿat ʾan tashraḥa n-natījata biwuḍūḥ.
She was able to explain the result clearly.
Adding على to استطاع by analogy with قدر
❌ استطاع على حل المشكلة.
Incorrect in the ordinary استطاع frame—use a direct verbal noun or أن-clause; على belongs to قدر على.
✅ استطاع حل المشكلة.
istaṭāʿa ḥalla l-mushkila.
He managed to solve the problem.
Key Takeaways
- استطاع is irregular hollow Form X from ط-و-ع: استطاع، يستطيع، استطعت، لم يستطع.
- Use أن + subjunctive or a direct verbal noun for the enabled action.
- Affirmative past استطاع often means “managed”; كان يستطيع is clearer for unrealized past capacity.
- Do not add على to استطاع; reserve it for the common قدر على frame.
- Passive لا يستطاع and قدر المستطاع are useful formal fixed patterns.
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