Arabic
| Key Takeaways |
| Arabic irregular verbs (الأفعال المعتلة, Al-Af’āl Al-Mu’tallah) contain one or more “weak letters” — ا، و، ي — that cause spelling and vowel changes during conjugation. |
| The four main types of irregular verbs are: مثال (Mithāl — weak first letter), أجوف (Ajwaf — weak middle letter), ناقص (Nāqis — weak final letter), and لفيف (Lafīf — two weak letters). |
| Weak letters are often deleted or replaced during conjugation, unlike regular verbs where the root remains visually stable across all forms. |
| Understanding the three-letter root system (الجذر, Al-Jithr) is essential before studying irregular verbs, as irregularity is always root-based, not random. |
Arabic learners frequently hit a wall at the same point: they master regular verb conjugation, then open the Quran or a classical text and find verbs that seem to break every rule they learned. The letters shift, disappear, or merge — and suddenly a familiar root becomes unrecognizable.
Irregular verbs in Arabic follow specific, learnable patterns governed by classical Arabic grammar (الصرف, Al-Sarf). Once you understand why weak letters behave the way they do, what felt chaotic becomes entirely predictable — and your ability to read, understand, and use Arabic verbs across all forms accelerates significantly.
Table of Contents:
What Are Irregular Verbs in Arabic?
Irregular verbs in Arabic — called الأفعال المعتلة (Al-Af’āl Al-Mu’tallah, literally “the diseased verbs”) — are verbs whose three-letter root contains at least one of the three weak letters: و (wāw), ي (yā’), or ا (alif).
These weak letters are phonetically unstable, meaning they change, merge, or drop entirely when surrounded by certain vowel patterns during conjugation.
How Do Irregular Verbs Differ from Regular Verbs in Arabic?
A regular verb (الفعل الصحيح, Al-Fi’l Al-Sahīh) keeps all three root letters visible and stable in every conjugation. Consider كَتَبَ (kataba — he wrote): in every form, the letters ك, ت, ب remain present and clear. An irregular verb like قَالَ (qāla — he said) comes from the root ق-و-ل, but the و transforms into an elongated alif in the past tense and disappears entirely in some present-tense forms.
This is the core distinction students must internalize before conjugating a single irregular verb.
Why Does Arabic Grammar Call Irregular Verbs “Mu’tallah” (Diseased)?
Classical Arabic grammarians (النحاة, Al-Nuhāt) used the term معتلة (mu’tallah) because the weak letters behave like an “illness” in the root — they resist the standard voweling rules that healthy (صحيح, sahīh) verbs follow smoothly.
This is not a modern teaching metaphor. It is the established Arabic morphological terminology (Al-Sarf) used in every classical grammar text, including Ibn Ājurrūmīyya and Alfiyya Ibn Mālik.
If you are working through our beginner-friendly Arabic grammar guide and finding verb tables confusing, irregular verbs are almost certainly where that confusion originates.
What Are the Main Types of Irregular Verbs in Arabic?
Arabic morphology divides irregular verbs into four main categories based on which position in the three-letter root the weak letter occupies. Each type produces different conjugation changes.
| Type (Arabic) | Transliteration | Weak Letter Position | Example Root | Example Verb |
| الفعل المثال (Al-Fi’l Al-Mithāl) | Mithāl | First letter (الفاء, Al-Fā’) | و-ع-د | وَعَدَ (wa’ada — he promised) |
| الفعل الأجوف (Al-Fi’l Al-Ajwaf) | Ajwaf | Middle letter (العين, Al-‘Ayn) | ق-و-ل | قَالَ (qāla — he said) |
| الفعل الناقص (Al-Fi’l Al-Nāqis) | Nāqis | Last letter (اللام, Al-Lām) | د-ع-و | دَعَا (da’ā — he called) |
| الفعل اللفيف (Al-Fi’l Al-Lafīf) | Lafīf | Two weak letters | و-ق-ي | وَقَى (waqā — he protected) |
Each category has its own conjugation rules. We will examine the three most common ones with full examples.
How Does the Mithāl Verb (الفعل المثال) Conjugate?
The مثال (Mithāl) verb has a weak letter as its first root letter — almost always و (wāw). In the past tense (الماضي, Al-Mādi), this verb conjugates almost like a regular verb because the و does not cause problems at the beginning of a past-tense form.
The irregularity appears in the present tense (المضارع, Al-Mudāri’), where the initial و is almost always deleted.
Mithāl Conjugation Example: وَعَدَ (wa’ada — he promised)
| Form | Arabic | Transliteration | Meaning |
| Past (3rd masc. sing.) | وَعَدَ | wa’ada | He promised |
| Present (3rd masc. sing.) | يَعِدُ | ya’idu | He promises |
| Command (أمر, Amr) | عِدْ | ‘id | Promise! |
| Verbal noun (مصدر, Masdar) | وَعْدٌ | wa’dun | A promise |
Notice the و disappears entirely in يَعِدُ (ya’idu) and عِدْ (‘id). This is the signature behavior of Mithāl verbs: the present tense drops the initial weak letter, leaving only two visible root consonants.
A Quranic example of this verb appears in (Al-Imran 3:194):
وَآتِنَا مَا وَعَدتَّنَا عَلَىٰ رُسُلِكَ
Wa’ātinā mā wa’adtanā ‘alā rusulika
“And grant us what You promised us through Your messengers.”
وَعَدتَّنَا is a Mithāl past-tense verb with the و fully visible, because past-tense Mithāl forms retain the initial weak letter.
Read also:Understanding Arabic Verbs
How Does the Ajwaf Verb (الفعل الأجوف) Conjugate?
The أجوف (Ajwaf, literally “hollow”) verb has its weak letter — و or ي — in the middle root position. This is the most commonly encountered irregular verb type in both the Quran and Modern Standard Arabic, and the changes it undergoes are the most dramatic.
In the past tense, the middle weak letter lengthens into a long vowel. In the present tense, it may shorten or change form. In negated or jussive forms (المجزوم, Al-Majzūm), it is often deleted entirely.
Ajwaf Conjugation Example: قَالَ (qāla — he said) | Root: ق-و-ل
| Form | Arabic | Transliteration | Meaning |
| Past (3rd masc. sing.) | قَالَ | qāla | He said |
| Present (3rd masc. sing.) | يَقُولُ | yaqūlu | He says |
| Jussive / Negated (لم) | لَمْ يَقُلْ | lam yaqul | He did not say |
| Command | قُلْ | qul | Say! |
The root و in ق-و-ل becomes the long vowel ā in qāla, becomes ū in yaqūlu, and disappears completely in lam yaqul and qul. This is not random — it follows the classical vowel-harmony rules of Arabic morphology (Al-I’lāl, الإعلال).
Ajwaf Conjugation Example: بَاعَ (bā’a — he sold) | Root: ب-ي-ع
| Form | Arabic | Transliteration | Meaning |
| Past (3rd masc. sing.) | بَاعَ | bā’a | He sold |
| Present (3rd masc. sing.) | يَبِيعُ | yabī’u | He sells |
| Jussive / Negated (لم) | لَمْ يَبِعْ | lam yabi’ | He did not sell |
| Command | بِعْ | bi’ | Sell! |
In our Arabic Grammar Course sessions, Ajwaf verbs consistently produce the most confusion for English-speaking students — specifically the jussive form where the middle letter vanishes. Students see لَمْ يَقُلْ and do not recognize it as coming from قَالَ at all. The key we teach is: always return to the three-letter root first.
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How Does the Nāqis Verb (الفعل الناقص) Conjugate?
The ناقص (Nāqis, literally “deficient”) verb has its weak letter — و or ي — as the final root letter. These verbs appear constantly in the Quran and in everyday Arabic. They are recognizable by endings that seem to vary dramatically across conjugation forms.
The past tense third-person masculine singular of Nāqis verbs ends in an alif maqsūra (ى) or a regular alif (ا).
Nāqis Conjugation Example: دَعَا (da’ā — he called/invoked) | Root: د-ع-و
| Form | Arabic | Transliteration | Meaning |
| Past (3rd masc. sing.) | دَعَا | da’ā | He called |
| Past (3rd fem. sing.) | دَعَتْ | da’at | She called |
| Present (3rd masc. sing.) | يَدْعُو | yad’ū | He calls |
| Present (3rd fem. sing.) | تَدْعُو | tad’ū | She calls |
| Jussive / Negated (لم) | لَمْ يَدْعُ | lam yad’u | He did not call |
| Command | اُدْعُ | ud’u | Call! |
Nāqis Conjugation Example: مَشَى (mashā — he walked) | Root: م-ش-ي
| Form | Arabic | Transliteration | Meaning |
| Past (3rd masc. sing.) | مَشَى | mashā | He walked |
| Past (3rd fem. sing.) | مَشَتْ | mashat | She walked |
| Present (3rd masc. sing.) | يَمْشِي | yamshī | He walks |
| Jussive / Negated (لم) | لَمْ يَمْشِ | lam yamshi | He did not walk |
| Command | اِمْشِ | imshi | Walk! |
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Get Your Free TrialWhat Is the Lafīf Verb (الفعل اللفيف) and How Does It Work?
The لفيف (Lafīf, literally “entwined”) verb contains two weak letters in its root. This is the rarest and most complex type. It splits into two subcategories:
لفيف مقرون (Lafīf Maqrūn — the two weak letters are adjacent): such as طَوَى (tawā — he folded) from root ط-و-ي.
لفيف مفروق (Lafīf Mafrūq — the two weak letters are separated by a healthy letter): such as وَقَى (waqā — he protected) from root و-ق-ي.
| Type | Arabic Term | Example Verb | Root | Meaning |
| Two adjacent weak letters | لفيف مقرون | طَوَى | ط-و-ي | He folded |
| Two separated weak letters | لفيف مفروق | وَقَى | و-ق-ي | He protected |
Lafīf verbs apply the conjugation rules of both Mithāl and Nāqis (for Mafrūq) or Ajwaf and Nāqis (for Maqrūn) simultaneously.
In our Online Arabic Classes, we introduce Lafīf only after students have fully internalized the single-weak-letter categories — attempting all four types simultaneously almost always leads to confusion and discouragement.
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What Are the Most Common Irregular Verbs in Arabic?
Below is a focused reference table of high-frequency irregular verbs — verbs you will encounter repeatedly in the Quran, in news Arabic, and in everyday speech.
| Arabic Verb | Transliteration | Root | Type | Meaning |
| قَالَ | qāla | ق-و-ل | أجوف | He said |
| كَانَ | kāna | ك-و-ن | أجوف | He was |
| جَاءَ | jā’a | ج-ي-أ | أجوف (Hamzated) | He came |
| أَرَادَ | arāda | ر-و-د | أجوف (Form IV) | He wanted |
| دَعَا | da’ā | د-ع-و | ناقص | He called |
| أَعْطَى | a’tā | ع-ط-و | ناقص (Form IV) | He gave |
| وَجَدَ | wajada | و-ج-د | مثال | He found |
| وَعَدَ | wa’ada | و-ع-د | مثال | He promised |
| صَلَّى | sallā | ص-ل-و | ناقص (Form II) | He prayed |
| هَدَى | hadā | ه-د-ي | ناقص | He guided |
كَانَ (kāna — he was) is particularly important because it functions as a copula verb in Arabic sentences and appears in hundreds of Quranic verses. Its conjugation follows Ajwaf rules exactly, which means the middle و disappears in jussive forms: لَمْ يَكُنْ (lam yakun — he was not).
Understanding these verbs is foundational to reading Arabic fluently. Our guide on mastering Arabic vocabulary pairs well with this verb study — because recognizing a root despite irregular surface forms is a vocabulary skill as much as a grammar skill.
Our Arabic for Beginners course builds the root-recognition skills that make irregular verb study manageable.
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How Do Regular and Irregular Verbs in Arabic Compare in Conjugation?
The clearest way to see the difference between regular and irregular verbs is to conjugate both through the same set of forms side by side.
Below we compare كَتَبَ (kataba — he wrote, regular) with قَالَ (qāla — he said, Ajwaf irregular):
| Grammatical Form | كَتَبَ (Regular) | قَالَ (Irregular — Ajwaf) |
| Past 3rd masc. sing. | كَتَبَ kataba | قَالَ qāla |
| Past 3rd fem. sing. | كَتَبَتْ katabat | قَالَتْ qālat |
| Present 3rd masc. sing. | يَكْتُبُ yaktubu | يَقُولُ yaqūlu |
| Negated past (لم + jussive) | لَمْ يَكْتُبْ lam yaktub | لَمْ يَقُلْ lam yaqul |
| Command (masc. sing.) | اُكْتُبْ uktub | قُلْ qul |
| Active participle (اسم فاعل) | كَاتِبٌ kātibun | قَائِلٌ qā’ilun |
The regular verb maintains all three root consonants in every form. The Ajwaf verb loses its middle letter in the jussive and command forms — a shift that only makes sense once you understand the underlying principle: Arabic phonology resists placing a weak letter between two sukūns (vowelless consonants).
This is the structural logic of Al-I’lāl (الإعلال) — the morphological process of weak-letter substitution and deletion. It is not arbitrary.
Every change is phonologically motivated, and classical Arabic grammar gives a precise rule for each case.
Students who learn the why behind each change memorize patterns far faster than those who try to memorize individual forms as exceptions.
Irregular Verbs in Arabic with Examples from Quranic Sentences
Seeing these verbs in complete Quranic sentences — not just in isolated tables — is how fluency actually builds. Here are several carefully selected examples that English-speaking students will encounter early in Quran study.
Example 1 — كَانَ (Ajwaf, “he was”):
إِنَّ اللَّهَ كَانَ عَلِيمًا حَكِيمًا
Inna Allāha kāna ‘alīman hakīmā
“Indeed, Allah is ever Knowing and Wise.” (An-Nisa 4:11)
كَانَ here is the Ajwaf past tense of root ك-و-ن. The و is absorbed into the long ā vowel.
Example 2 — يَدْعُو (Nāqis, “he calls”):
وَاللَّهُ يَدْعُو إِلَىٰ دَارِ السَّلَامِ
Wa-Allāhu yad’ū ilā dāri as-salām
“And Allah invites to the Home of Peace.” (Yunus 10:25)
يَدْعُو is the present tense of Nāqis verb دَعَا. The final root و appears as a long ū vowel in the present tense.
Example 3 — قُلْ (Ajwaf command, from قَالَ):
قُلْ هُوَ اللَّهُ أَحَدٌ
Qul huwa Allāhu ahad
“Say: He is Allah, the One.” (Al-Ikhlas 112:1)
قُلْ is the singular command of the Ajwaf verb قَالَ. The root و is deleted because the command form creates a sukūn environment where the weak letter cannot survive.
These three examples alone cover Ajwaf and Nāqis verbs in their most important conjugated forms. For anyone working through the Quran, these are not rare encounters — they appear on virtually every page.
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Arabic irregular verbs follow logical, rule-governed patterns — but those patterns need an expert teacher to explain them clearly, with the right sequencing and sufficient practice.
At Buruj Academy, our Arabic Grammar Course is taught by Al-Azhar University graduates with 12+ years of experience guiding non-Arabic speakers through exactly these morphological patterns.
We apply the Buruj Method — context-before-abstraction — meaning students encounter verbs in real sentences before memorizing abstract conjugation tables.
Our Arabic for Beginners course builds the root-recognition skills that make irregular verb study manageable, and our Quranic Arabic Classes apply these same patterns directly to Quran comprehension.
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Get Your Free TrialConclusion
Irregular verbs in Arabic are not exceptions to the system — they are part of the system, governed by centuries-old morphological principles that classical grammarians documented with precision. The moment students stop seeing these verbs as random and start reading their roots, the entire landscape of Arabic conjugation becomes far more navigable.
The four types — Mithāl, Ajwaf, Nāqis, and Lafīf — each follow their own internal logic. Master one type fully before moving to the next, always anchor new forms to the three-letter root, and practice consistently through real Quranic and MSA sentences.
Frequently Asked Questions About Irregular Verbs in Arabic
What Are Irregular Verbs Called in Arabic Grammar?
Irregular verbs in Arabic are called الأفعال المعتلة (Al-Af’āl Al-Mu’tallah). The term mu’tallah means “diseased” or “weak,” referring to the presence of one or more weak letters — و, ي, or ا — in the three-letter root. These weak letters cause predictable changes in voweling and spelling during conjugation, unlike fully sound (sahīh) verbs.
How Many Types of Irregular Verbs Exist in Arabic?
Arabic morphology (Al-Sarf, الصرف) identifies four main types of irregular verbs: مثال (Mithāl — weak first letter), أجوف (Ajwaf — weak middle letter), ناقص (Nāqis — weak final letter), and لفيف (Lafīf — two weak letters). Most students encounter Ajwaf and Nāqis most frequently because these types include the highest-frequency verbs in both Quranic and Modern Standard Arabic.
Is كَانَ an Irregular Verb in Arabic?
Yes. كَانَ (kāna — he was) is an Ajwaf irregular verb from the root ك-و-ن. Its middle و transforms into a long ā vowel in the past tense and shortens in other forms. In the jussive form (لَمْ يَكُنْ, lam yakun), the و disappears entirely. It is one of the most important irregular verbs to master because of its constant use in Arabic and the Quran.
Do Irregular Verbs in Arabic Follow Predictable Rules?
Yes — completely. Every change in an irregular verb follows the principle of الإعلال (Al-I’lāl), which governs how weak letters behave when vowel environments make them phonologically unstable. Once learners understand the three weak letters and how each behaves in the first, middle, or final root position, they can predict conjugation changes rather than memorizing each form individually. This is exactly the approach we teach in our Arabic Grammar Course.
