Adjectives

An adjective in Arabic is, grammatically, a kind of noun — and like any noun, it has to agree.

An Arabic adjective comes after the noun it modifies and matches it on four axes at once: gender, number, definiteness, and case. The agreement is mechanical and mostly transparent, with one notable wrinkle for non-human plurals and a special set of patterns for colors and bodily defects. English speakers find adjectives easier than nouns or verbs, once they accept that the adjective comes second and that "a big house" is literally "a-house big."

The basic rule

The adjective follows the noun and copies its gender, number, definiteness, and case.

The repetition of al- on the adjective is what tells you it is an attributive adjective rather than a predicate. Without the repeated article, the meaning shifts:

Plural agreement — and the rule everyone trips on

For human plurals, agreement is straightforward. A masculine human plural takes a masculine plural adjective (often the sound plural -uun/-iin); a feminine human plural takes -aat. But for plural nouns referring to non-humans — animals, objects, abstract things — the adjective is feminine singular. Every time. This is the single most counter-intuitive rule for English speakers and the one to drill until it feels automatic.

Colors and defects: the afʿal / faʿlaa' pattern

Adjectives that name primary colors or bodily defects (deaf, blind, lame, etc.) follow a special pair of patterns: afʿal for masculine, faʿlaa' for feminine. These adjectives do not take al-'s tanwiin partner — they are diptotes — but otherwise behave like ordinary adjectives.

The same afʿal pattern is also the comparative shape (akbar, "bigger"; akthar, "more"). Comparatives don't change for gender or number — they are invariant.

A larger set of examples

Why English speakers find this easy — and where they slip

The system is regular. Once you know the noun's gender and number, the adjective form is essentially determined. There is none of the genuine unpredictability of, say, German adjective endings. Two specific traps recur. First, forgetting to repeat al- on the adjective when the noun is definite — the thing that turns "the big book" into "the book is big." Second, falling out of the non-human-plural rule under conversational pressure. You will produce al-kutub al-kabiira ("the big books") about twenty times before it becomes automatic.

What it's called in the Arabic tradition

An adjective is صِفَة (Sifa) or, more technically, نَعْت (naʿt). The noun it modifies is مَنْعوت (manʿuut). The relational -iyy suffix that turns "Arab" into "Arabic" is نِسْبَة (nisba). The afʿal pattern, when used as a comparative, is اِسْم التَّفْضيل (ism at-tafDiil).