Arabic has two closely related contrast markers written with the same base letters in ordinary unvocalized text. Light لكنْ introduces a contrasting clause without governing its case or mood. Heavy لكنّ belongs to the إنّ family: it opens a nominal clause, makes its noun accusative, and leaves a one-word predicate nominative.
Both commonly translate as “but” or “however,” so English does not reveal which structure Arabic needs. Look instead at the grammar after the particle. A verbal clause readily follows light لكنْ. A nominal clause can follow either form, but its subject stays nominative after light لكنْ and becomes the accusative noun of heavy لكنّ; attached ـه، ـها، ـنا likewise identify the heavy form.
Heavy لكنّ shares its case pattern with the family introduced on the إنّ particle page.
Light لكنْ links a contrasting clause
Light لكنْ (formal neutral) asserts that the second clause qualifies, corrects, or runs against an expectation created by the first. It does not itself change the following verb’s mood.
اتصلنا بالمكتب، لكن لم يجب أحد.
ittaṣalnā bil-maktabi, lākin lam yujib ʾaḥad.
We called the office, but no one answered. (Formal neutral.)
Build the sentence from two independent clauses: اتصلنا بالمكتب “we called the office” and لم يجب أحد “no one answered.” Light لكنْ marks the second as contrary to the expectation that a call would receive an answer. لم, not لكنْ, makes يجبْ jussive.
وصل القطار في موعده، لكن تأخر خروج الركاب.
waṣala l-qiṭāru fī mawʿidihi, lākin taʾakhkhara khurūju r-rukkāb.
The train arrived on time, but the passengers were delayed in getting out. (Formal report.)
The subjects need not match. The first clause is about القطار; the second is about خروج الركاب. A contrast linker does not make one noun the subject of every coordinated verb.
لا يعترض الخبراء على الهدف، لكن يختلفون حول طريقة التنفيذ.
lā yaʿtariḍu l-khubarāʾu ʿalā l-hadafi, lākin yakhtalifūna ḥawla ṭarīqati t-tanfīdh.
The experts do not object to the goal, but they disagree about the method of implementation. (Formal.)
Here يختلفونَ remains indicative. Light لكنْ supplies contrast, not mood government.
Light لكنْ can also introduce a complete nominal clause without governing its subject:
الملخص واضح، لكن بعض التفاصيل تحتاج إلى توثيق.
al-mulakhkhaṣu wāḍiḥun, lākin baʿḍu t-tafāṣīli taḥtāju ʾilā tawthīq.
The summary is clear, but some details need documentation. (Formal neutral; بعضُ remains nominative.)
Heavy لكنّ governs a nominal clause
Heavy لكنّ works like a member of the إنّ family. Its noun is accusative; a simple nominal predicate is nominative. In ordinary unvocalized spelling, the shadda is usually absent, so syntax must identify the form.
الموعد قريب، لكن الفريق مستعد.
al-mawʿidu qarībun, lākinna l-farīqa mustaʿidd.
The deadline is near, but the team is ready. (Formal neutral.)
In careful analysis, الفريقَ is the accusative noun of لكنّ, while مستعدٌّ is its nominative predicate. Natural pause hides the final case ending of the last word, but the grammar remains.
An attached pronoun can fill the noun slot. This pattern is extremely common because it resumes the previous topic compactly:
الخطة مكلفة، لكنها ضرورية في هذه المرحلة.
al-khuṭṭatu mukallifatun, lākinnahā ḍarūriyyatun fī hādhihi l-marḥala(h).
The plan is expensive, but it is necessary at this stage. (Formal neutral.)
لم نصل إلى اتفاق، لكننا حددنا نقاط الخلاف بدقة.
lam naṣil ʾilā ttifāqin, lākinnanā ḥaddadnā niqāṭa l-khilāfi bi-diqqa(h).
We did not reach an agreement, but we identified the points of disagreement precisely. (Formal.)
In لكننا, attached نا is the noun of لكنّ; the perfect verbal sentence حددنا... is its predicate. The embedded predicate is not forced into the subjunctive or jussive.
وَلَكِنْ and وَلَكِنَّ
The prefixed conjunction و often precedes either form: ولكنْ before a verbal contrast and ولكنّ before a governed nominal clause. Write و attached to لكن, but do not write an invented alif inside the word: standard spelling is لكن, not لاكن.
اقترحت اللجنة خفض النفقات، ولكن رفض المجلس تقليص الخدمات.
iqtaraḥati l-lajnatu khafḍa n-nafaqāti, wa-lākin rafaḍa l-majlisu taqlīṣa l-khidmāt.
The committee proposed reducing expenditure, but the council rejected cutting services. (Formal policy register.)
البيانات محدودة، ولكن نتائجها جديرة بالمناقشة.
al-bayānātu maḥdūdatun, wa-lākinna natāʾijahā jadīratun bil-munāqasha(h).
The data are limited, but their results are worthy of discussion. (Academic.)
Because نتائج is a nonhuman plural, its adjective predicate is feminine singular: جديرةٌ. Heavy لكنّ changes the case of نتائجَ, not the agreement rule.
Traditional grammar also recognizes coordinating light لكنْ between single words after negation or prohibition, as in highly edited or literary patterns equivalent to “not X but Y.” That use is correct (literary/formal) but restricted. Contemporary prose normally avoids forcing it into every English “not X but Y”; بل, وإنما, or a full contrasting clause is often clearer.
Reversing the contrast changes the point
Either proposition can come first, but reversal changes which expectation the writer cancels:
الطريق طويل، لكن المناظر جميلة.
aṭ-ṭarīqu ṭawīlun, lākinna l-manāẓira jamīla(h).
The road is long, but the scenery is beautiful. (The second clause softens a negative impression.)
المناظر جميلة، لكن الطريق طويل.
al-manāẓiru jamīlatun, lākinna ṭ-ṭarīqa ṭawīl.
The scenery is beautiful, but the road is long. (The second clause adds a reservation.)
The facts are the same, but the argumentative direction is not. Unlike temporal ثمّ, لكنّ does not order events; it manages expectations.
Tense, mood, and clustered particles
Each clause locates its own event in time. A past reporting verb does not mechanically force a past tense in its reported content.
قالت المديرة إن التمويل سيتأخر، لكن الفريق لن يتخلى عن المشروع.
qālati l-mudīratu ʾinna t-tamwīla sa-yataʾakhkharu, lākinna l-farīqa lan yatakhallā ʿani l-mashrūʿ.
The director said that funding would be delayed, but the team would not abandon the project. (Formal.)
Heavy لكنّ makes الفريقَ accusative. لن independently governs subjunctive يتخلّى; its final alif maqṣūra hides the mood ending in spelling.
تأخر الإشعار، لكن الموظفين لن يهملوا الطلبات العاجلة.
taʾakhkhara l-ʾishʿāru, lākinna l-muwaẓẓafīna lan yuhmilū ṭ-ṭalabāti l-ʿājila(h).
The notice was delayed, but the employees will not neglect urgent requests. (Formal.)
The five-verb form يهملونَ loses its mood nūn after لن, becoming يهملوا. Neither light nor heavy لكن causes that deletion.
Punctuation and paragraph-level contrast
A comma is useful before لكن when it joins two substantial clauses. With very long or internally punctuated clauses, a semicolon can make the contrast clearer. Do not imitate the English rule mechanically: punctuation depends on Arabic clause weight, and a comma never substitutes for a missing linker.
أظهر المسح ارتفاع رضا المستخدمين عن سرعة الخدمة، لكن النتائج لا تشمل المناطق الريفية؛ ولذلك لا يمكن تعميم الاستنتاج على جميع السكان، ولكنها توفر أساسا مفيدا لدراسة أوسع.
ʾaẓhara l-masḥu rtifāʿa riḍā l-mustakhdimīna ʿan surʿati l-khidmati, lākini n-natāʾiju lā tashmalu l-manāṭiqa r-rīfiyyata; wa-lidhālika lā yumkinu taʿmīmu l-istintāji ʿalā jamīʿi s-sukkāni, wa-lākinnahā tuwaffiru ʾasāsan mufīdan li-dirāsatin ʾawsaʿ.
The survey showed increased user satisfaction with service speed, but the results do not cover rural areas; the conclusion therefore cannot be generalized to the entire population, although the results do provide a useful basis for a broader study. (Academic.)
The first marker is light لكنْ: it leaves nominal-clause subject النتائجُ nominative, and لا تشمل is that subject's verbal predicate. The last is heavy لكنّها, whose pronoun resumes النتائج; because that antecedent is a nonhuman plural, the predicate verb is feminine singular توفر.
Common Mistakes
Copying an English comma or writing لاكن
❌ التقرير مختصر، لاكن يغطي النقاط الأساسية.
Incorrect spelling and linkage—standard Arabic writes لكن without an internal alif.
✅ التقرير مختصر، لكنه يغطي النقاط الأساسية بوضوح.
at-taqrīru mukhtaṣarun, lākinnahu yughaṭṭī n-niqāṭa l-ʾasāsiyyata bi-wuḍūḥ.
The report is concise, but it clearly covers the essential points.
Missing case government after heavy لكنّ
❌ الموعد مناسب، لكن المشاركون غير متاحين صباحا.
Incorrect under the intended heavy reading lākinn: its sound masculine plural noun must be accusative المشاركينَ. In unvocalized text, this wording is grammatical only if لكن is instead read as light lākin.
✅ الموعد مناسب، لكن المشاركين غير متاحين صباحا.
al-mawʿidu munāsibun, lākinna l-mushārikīna ghayru mutāḥīna ṣabāḥan.
The appointment time is suitable, but the participants are unavailable in the morning.
Ordinary spelling leaves the two readings visually identical at لكن. The visible ـون / ـين ending on a sound masculine plural therefore helps expose whether the intended syntax and the following case form match.
Confusing أنْ with أنّ inside the contrast
❌ نؤيد الاقتراح، لكننا نريد أن التنفيذ يبدأ تدريجيا.
Incorrect—the intended verbal complement requires light أنْ plus subjunctive يبدأَ.
✅ نؤيد الاقتراح، لكننا نريد أن يبدأ التنفيذ تدريجيا.
nuʾayyidu l-iqtirāḥa, lākinnanā nurīdu ʾan yabdaʾa t-tanfīdhu tadrījiyyan.
We support the proposal, but we want implementation to begin gradually.
Replacing required conditional فـ with لكن
❌ إن تعذر الإصلاح لكن الاستبدال ضروري.
Incorrect—لكن marks contrast, not the required link before this nominal conditional result.
✅ إن تعذر الإصلاح فالاستبدال ضروري قبل التشغيل.
ʾin taʿadhdhara l-ʾiṣlāḥu fa-l-istibdālu ḍarūriyyun qabla t-tashghīl.
If repair is impossible, replacement is necessary before operation.
Backshifting merely because the reporting verb is past
❌ أوضح المتحدث أن الاجتماع انتهى غدا، لكنه سيجيب عن الأسئلة اليوم.
Incorrect time reference—the meeting was future from the past statement, so use سينتهي rather than a mechanically past verb.
✅ أوضح المتحدث أن الاجتماع سينتهي غدا، لكنه سيجيب عن الأسئلة اليوم.
ʾawḍaḥa l-mutaḥaddithu ʾanna l-ijtimāʿa sa-yantahī ghadan, lākinnahu sa-yujību ʿani l-ʾasʾilati l-yawm.
The speaker explained that the meeting would end tomorrow, but that he would answer questions today.
Key Takeaways
- Light لكنْ links a contrasting clause and does not govern its verb.
- Heavy لكنّ opens a nominal clause: its noun is accusative, while a simple predicate is nominative.
- Ordinary unvocalized spelling hides the sukūn/shadda contrast; identify the structure after the particle.
- Write لكن without an internal alif, attach preceding و, and use punctuation to clarify longer clause boundaries.
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- Delayed Sequence with ثمّB1 — Use ثمّ to present a later event, stage, or argument as distinct from what came before.
- أو versus أمA2 — Choose أو for ordinary alternatives and approximation, and أم for a closed alternative question that demands a choice.
- Coordination with وA2 — Coordinate words, phrases, and clauses with و while preserving parallel case, mood, agreement, reference, and discourse relations.