Learn Arabic Sarf (Morphology)
A path through Arabic morphology — from root letters to derived forms and applying patterns to real text.
Sarf (الصرف) is the study of how Arabic words are formed — how a small set of root letters expands into nouns, verbs, and participles by following predictable patterns.
If Nahw tells you how words behave in a sentence, Sarf tells you where the words themselves come from.
Most Arabic words come from a trilateral root — three consonants that carry the core meaning. For example ك‑ت‑ب carries the idea of writing:
- كَتَبَ — he wrote
- كِتَاب — book
- مَكْتَب — desk / office
- كَاتِب — writer
A smaller group of words use quadrilateral roots (four letters), e.g. ت‑ر‑ج‑م (to translate).
A wazn (literally “weight”) is a template that root letters drop into. The classical placeholder root is ف‑ع‑ل, so patterns are written using ف, ع, ل.
Examples on root ك‑ت‑ب:
| Pattern | Word | Meaning |
|---|---|---|
| فَعَلَ | كَتَبَ | he wrote |
| فَاعِل | كَاتِب | writer |
| مَفْعُول | مَكْتُوب | written |
| فِعَال | كِتَاب | book |
Learn the patterns and you can decode thousands of words.
The past tense (al-māḍī) describes a completed action. The base form is the 3rd-person masculine singular: فَعَلَ (“he did”).
- نَصَرَ — he helped
- ذَهَبَ — he went
- سَمِعَ — he heard
This is the form you’ll see listed in a dictionary.
The present/imperfect tense (al-muḍāriʿ) describes an ongoing or future action. It’s built by prefixing one of أ‑ت‑ي‑ن to the root and adjusting vowels:
- يَنْصُرُ — he helps / will help
- يَذْهَبُ — he goes
- يَسْمَعُ — he hears
The middle vowel often differs from the past form and is memorized per verb.
Each verb conjugates across 14 pronoun forms (3 persons × singular / dual / plural × masculine / feminine, with overlaps). For example, past tense of نصر:
- هو نَصَرَ — he helped
- هي نَصَرَتْ — she helped
- هم نَصَرُوا — they (m.) helped
- أنا نَصَرْتُ — I helped
- نحن نَصَرْنَا — we helped
Drilling the full table for one verb makes every other regular verb easy.
Arabic verbs are classified by which letters appear in their root. The classification matters because weak letters (و, ي, ا, ء) trigger predictable spelling changes during conjugation.
The five families branching from this node cover every regular Arabic verb. Once you can identify which family a verb belongs to, its conjugation quirks become predictable.
The “regular” family — all three root letters are strong (no hamza, no weak letter, no doubling). Conjugation follows the textbook patterns with no surprises.
Examples: نَصَرَ, كَتَبَ, ضَرَبَ, جَلَسَ.
Master sound verbs first; everything else is a variation on these.
A root that contains a hamza (ء) as one of its three letters. Sub-types by hamza position:
- Mahmūz al-fā’ — hamza is the first letter (e.g. أَكَلَ — to eat).
- Mahmūz al-ʿayn — hamza is the middle letter (e.g. سَأَلَ — to ask).
- Mahmūz al-lām — hamza is the last letter (e.g. قَرَأَ — to read).
The conjugation is mostly regular; the spelling of the hamza follows a few extra rules.
A root whose second and third letters are identical, written with a shadda. Examples:
- مَدَّ (root م‑د‑د) — to extend
- رَدَّ (root ر‑د‑د) — to return
- شَكَّ (root ش‑ك‑ك) — to doubt
Conjugation usually keeps the shadda, but it splits in some forms (e.g. مَدَدْتُ — I extended).
A root whose middle letter is weak (و or ي), which then surfaces as a long ا in the past tense:
- قَالَ (root ق‑و‑ل) — to say
- بَاعَ (root ب‑ي‑ع) — to sell
- خَافَ (root خ‑و‑ف) — to fear
The middle letter shrinks or vanishes in certain conjugations (e.g. قُلْتُ — I said).
A root whose last letter is weak (و or ي). Examples:
- دَعَا (root د‑ع‑و) — to call / supplicate
- رَمَى (root ر‑م‑ي) — to throw
- بَكَى (root ب‑ك‑ي) — to weep
The final weak letter appears as ا or ى in the past, then changes shape across persons and tenses.
Beyond the simple Form I (فَعَلَ), Arabic builds 9 more derived verb forms (II–X) by adding letters or doubling consonants. Each form carries a typical shade of meaning:
- Form II فَعَّلَ — intensive / causative (kassara — he smashed)
- Form III فَاعَلَ — reciprocal (kātaba — he corresponded with)
- Form IV أَفْعَلَ — causative (aslama — he submitted)
- Form V تَفَعَّلَ — reflexive of II
- Form VII انْفَعَلَ — passive / reflexive
- Form VIII افْتَعَلَ — reflexive
- Form X اسْتَفْعَلَ — to seek / request
Knowing the form usually tells you the meaning at a glance.
- Active participle (اسم الفاعل) — the doer. Form I pattern: فَاعِل.
- كَاتِب — writer
- نَاصِر — helper
- Passive participle (اسم المفعول) — the thing acted upon. Form I
pattern: مَفْعُول.
- مَكْتُوب — written
- مَنْصُور — one who is helped
For Forms II–X, both participles start with مُ (e.g. مُسْلِم, مُجَاهِد).
The maṣdar is the noun form of the action itself — what English would express with “-ing” or “to ___”.
- نَصَرَ → نَصْر (helping / victory)
- كَتَبَ → كِتَابَة (writing)
- عَلِمَ → عِلْم (knowledge)
For Form I the maṣdar pattern is partly memorized; Forms II–X have predictable maṣdar patterns that come with practice.
Open a Qur’an page and try to spot:
- Roots — strip prefixes/suffixes, find the 3 core letters.
- Patterns — match the shape (فَاعِل, مَفْعُول, مُسْتَفْعِل…).
- Tense & person — past or present? Who is doing the action?
Even short āyāt are full of the patterns from this roadmap. Each verse you decode reinforces the entire system.
Consistency beats cramming. A simple daily loop:
- 5 min — conjugate one new verb across the 14 pronouns.
- 5 min — review yesterday’s verb (active recall).
- 5 min — pick one āyah, identify root + pattern of every verb.
Use the flashcard decks on this site to drill vocabulary while the patterns sink in.