In a nutshell: Arabic irregular verbs (الأفعال المعتلة) are verbs that deviate from regular conjugation patterns due to weak letters in their roots. These verbs are divided into four types: hollow, assimilated, defective, and doubly weak, each with unique conjugation rules.
It’s no secret that irregular verbs in Arabic الأفعال المعتلة (al-af‘āl al-mu‘tallah) are a stumbling block for many students of Arabic (and I don’t blame them!). But understanding the types of Arabic irregular verbs is essential for learning Arabic, as irregular verbs are frequently appeared in Arabic literature, daily speech, and Quranic verses.
For instance, the verse “ادْعُ إِلَىٰ سَبِيلِ رَبِّكَ بِالْحِكْمَةِ وَالْمَوْعِظَةِ الْحَسَنَةِ” (“Invite to the way of your Lord with wisdom and good instruction”) uses the verb دعا (daʻaa) in the imperative form wich is irregular verb.
That’s why I’m going to do my best to explain them in a way that actually makes sense.
What Are Irregular Verbs in Arabic?
Arabic irregular verbs, known as الأفعال المعتلة ( al-afʻaal al-muʻtallah), are verbs that deviate from the standard conjugation patterns of regular verbs due to the presence of one or more “weak” letters حروف العلة (hurūf al-‘illah) (و , ي , ا) within their triliteral root.
These weak letters are prone to undergoing various changes, including elision, substitution, or assimilation, depending on their position within the verb and the grammatical context.
This variability necessitates a distinct set of rules for conjugating irregular verbs in Arabic, making them a challenging aspect of Arabic morphology.
1- Hollow Verbs (الأجوف – al-ajwaf) Irregular Verbs
Hollow verbs, known in Arabic as الأجوف (al-ajwaf), are characterized by having a weak letter (حرف علة) in the middle of the root. This means the second radical of the verb’s root (عين الكلمة – ‘ayn al-kalimah) is a vowel, typically و (waw) or ي (ya). They are called “hollow” because the weak letter in the middle creates a “gap” when conjugated.
For example:
- قام (qaama) – “He stood.”
- نام (naama) – “He slept.”
- باع (ba‘a) – “He sold.”
قام (qaama)
“He stood.”
Root: ق و م (qawm).
Pattern: فَعَلَ (faʿala), but the middle weak letter (و) changes into ا.
Hollow verbs undergo changes when conjugated. The weak letter in the middle often changes, merges, or even disappears depending on the tense, mood, or attached pronouns.
Let’s take the verb “قام” as our example and explore its conjugation across the past, present, and imperative.
| Pronoun | Past Tense | Present Tense | Imperative |
| أنا (ana) | قُمتُ (qumtu) | أقومُ (aqūmu) | — |
| نحن (nahnu) | قُمنا (qumnā) | نقومُ (naqūmu) | — |
| أنت (anta) | قُمتَ (qumta) | تقومُ (taqūmu) | قُمْ (qum) |
| أنتِ (anti) | قُمتِ (qumti) | تقومينَ (taqūmīna) | قومي (qūmī) |
| أنتما (antumā) | قُمتُما (qumtumā) | تقومانِ (taqūmānī) | قوما (qūmā) |
| أنتم (antum) | قُمتُم (qumtum) | تقومونَ (taqūmūna) | قوموا (qūmū) |
| هو (huwa) | قامَ (qāma) | يقومُ (yaqūmu) | — |
| هي (hiya) | قامَت (qāmat) | تقومُ (taqūmu) | — |
| هما (humā) | قامَا (qāmā) | يقومانِ (yaqūmānī) | — |
| هم (hum) | قاموا (qāmū) | يقومونَ (yaqūmūna) | — |
2- The Assimilated Verbs (المثال – al-mithāl) Irregular Verbs
Assimilated verbs, known in Arabic as المثال (al-mithāl), are a fascinating category of irregular verbs. These verbs have a weak letter (حرف علة) at the beginning of their root, specifically in the فاء الكلمة (fa’ al-kalimah) position. The weak letter is either و (waw) or ي (ya), but it can never be ا (alif).
For instance:
- وزن (wazana) – “to weigh.”
- يبس (yabisa) – “to dry.”
- وهب (wahaba) – “to grant.”
- وعد (waʻada) – “to promise.”
Now, let’s see how these verbs change when conjugated. We’ll take the verb وَعَدَ (waʻada) as our example.
(Note: For simplicity, I’ll focus on the masculine singular forms in the past, present and imperative tenses.)
| Tense | Conjugation |
| Past Tense | وزنتُ (wazantu – I weighed), وزن (wazana – he weighed), وزنوا (wazanuu – they weighed) |
| Present | أزن (’azinu – I weigh), يزن (yazinu – he weighs), يزنون (yazinuuna – they weigh) |
| Imperative | زِنْ (zin – weigh!), زِنُوا (zinuu – weigh, plural!) |
See?
- In the past tense, the weak letter و remains intact in all forms.
- In the present tense, the و drops when conjugated, leaving أزن (’azinu) instead of أوزن (awzinu).
- In the imperative, the weak letter disappears entirely, simplifying the form to زِنْ (zin).
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Book Your Free Trial3- The Defective Verb (الفعل الناقص – al-naaqis) Irregular Verbs
Defective verbs, known as الفعل الناقص (al-naaqis) in Arabic, are verbs where the last root letter (لام الكلمة – lām al-kalimah) is a weak letter, either ا (alif), و (waw), or ى (ya).
Examples:
- دعا (daʻaa) – to call
- رمى (ramaa) – to throw
- بكى (bakaa) – to cry
Now, let’s see how these verbs change when conjugated. We’ll use the verb دعا (daʻaa) as our example.
| Tense | Pronoun | Conjugation | Meaning | Notes |
| Past | هو | دعا (daʻaa) | He called | The weak letter (alif) is present. |
| Present | هو | يدعو (yadʻuu) | He calls | The weak letter (alif) changes to waw (و) and a vowel is added before it. |
| Imperative | أنتَ | ادعُ (udʻu) | Call! | The weak letter disappears. |
Read also: Hollow verbs in Arabic
4- The Doubly Weak Verbs (اللفيف – al-lafīf) Irregular Verbs
Doubly weak verbs, known as الفعل اللفيف (al-lafīf) in Arabic, are verbs that contain two weak letters (حرفا علة). These verbs are further categorized into two subtypes based on the position of the weak letters:
- The Separated Doubly Weak Verb (لفيف مفروق – lafīf mafrooq)
- The Conjoined Doubly Weak Verb (لفيف مقرون – lafīf maqroon)
Give me your full attention here.
A. The Separated Doubly Weak Verb (لفيف مفروق – lafīf mafrooq)
In lafīf mafrooq, the first (فاء الفعل) and last (لام الفعل) root letters are weak letters, while the middle (عين الفعل) is a consonant. The weak letters are “separated” by the central consonant.
Examples
وَشَى (washā) – “to defame”
- Root letters: و-ش-ى (w-sh-aa)
- Structure: The فاء (first letter) is و, and the لام (last letter) is ى, with the consonant ش in between.
وَلِي (wali) – “to be near”
- Root letters: و-ل-ي (w-l-y)
- The فاء is و, the لام is ي, and the central ل is a consonant.
وَقَى (waqā) – “to protect”
- Root letters: و-ق-ى (w-q-y)
- The فاء is و, the لام is ى, and ق is a consonant.
Let’s take the verb وَشَى (washaa) as an example of conjugation:
| Tense | Pronoun | Conjugation | Meaning | Notes |
| Past | هو | وَشَى (washaa) | He gossiped | Both weak letters are present. |
| Present | هو | يَشي (yashī) | He gossips | The first weak letter (waw) disappears and the second weak letter (yaa) changes its vowel. |
| Imperative | أنتَ | شِ (shi) | Gossip! | Both weak letters disappear, and the imperative follows a unique pattern. |
B. The Conjoined Doubly Weak Verb (لفيف مقرون – lafīf maqroon)
In lafīf maqroon, the middle (عين) and last (لام) root letters are weak letters. The weak letters are “conjoined,” with no consonant separating them.
كَوَى (kawā) – “to iron”
- Root letters: ك-و-ى (k-w-y)
- Structure: The عين الفعل (middle letter) is و, and the لام الفعل (last letter) is ى.
لَوَى (lawā) – “to twist”
- Root letters: ل-و-ى (l-w-y)
- Structure: Both the عين الفعل and لام الفعل are weak letters (و and ى).
Now, let’s look at the verb لَوَى (lawaa) as an example of conjugation:
| Tense | Pronoun | Conjugation | Meaning | Notes |
| Past | هو | لَوى (lawaa) | He twisted | Both weak letters are present. |
| Present | هو | يَلْوي (yalwī) | He twists | The first weak letter (waw) is replaced by an alif (ا) and the second weak letter (yaa) loses its vowel. |
| Imperative | أنتَ | لِ (li) | Twist! | Both weak letters disappear, and the imperative follows a unique pattern. |
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Conclusion:
Arabic irregular verbs (الأفعال المعتلة) are a key challenge for learners, as they deviate from regular verb patterns due to weak letters (حروف العلة) such as و, ي, and ا in their roots. These irregular verbs appear frequently in everyday speech, literature, and Quranic texts.
They are classified into several types, including hollow verbs (الأجوف), where the middle root letter is weak; assimilated verbs (المثال), where the weak letter appears at the beginning of the root; and defective verbs (الفعل الناقص), where the last root letter is weak. Each type follows unique conjugation rules that change depending on tense and pronoun.
The fourth category, doubly weak verbs (اللفيف), includes two subtypes: separated doubly weak verbs (لفيف مفروق), where weak letters are separated by a consonant, and conjoined doubly weak verbs (لفيف مقرون), where weak letters are adjacent. Each type has specific patterns for conjugation across past, present, and imperative tenses, often altering the weak letters or even eliminating them.
FAQs about Arabic Irregular Verbs
Q1: What are Arabic irregular verbs (الأفعال المعتلة)?
A: Arabic irregular verbs, or al-af‘āl al-mu‘tallah, are verbs whose three-letter root contains one or more weak letters: Waw (و), Ya (ي), or Alif (ا). These weak letters undergo changes like dropping or transforming during conjugation, making them deviate from standard regular verb patterns.
Q2: What is a hollow verb (الأجوف) in Arabic grammar?
A: A hollow verb (al-ajwaf) is an irregular Arabic verb where the middle root letter (the second radical) is a weak vowel, usually Waw (و) or Ya (ي). For example, in qāma (قام), the middle weak letter often disappears or changes depending on the tense and pronoun used.
Q3: How do assimilated verbs (المثال) change during conjugation?
A: Assimilated verbs (al-mithāl) have a weak letter—either Waw (و) or Ya (ي)—at the very beginning of their root. While the weak letter remains fully intact during the past tense, it completely drops out in the present and imperative forms, such as wazana transforming into yazinu.
Q4: What is the difference between defective and doubly weak Arabic verbs?
A: Defective verbs (al-naaqis) have a single weak letter at the end of their root. Doubly weak verbs (al-lafīf) contain two weak letters. These are either separated by a normal consonant (lafīf mafrooq) or appear right next to each other as conjoined weak letters (lafīf maqroon).
Q5: Why is learning irregular Arabic verbs necessary for students?
A: Mastering irregular verbs is essential because they appear constantly across daily speech, classical Arabic literature, and the Holy Quran. Failing to recognize how weak letters transform makes it incredibly difficult to correctly identify root words or accurately form imperative commands and present-tense verbs.
