The Arabic nominal system, the regular pattern

Let’s begin by looking at the case-endings for the regular (sālim, سالم) pattern. 

	Singular			Dual
	Definite	Indefinite	Construct	Definite	Indefinite	Construct
marfū‘	-u	-un	-u	-āni	-āni	-ā
manṣūb	-a	-an	-a	-ayni	-ayni	-ay
majrūr	-i	-in	-i	-ayni	-ayni	-ay

This applies to all regular nouns and adjectives in the singular and the dual, whether they are masculine or feminine. Nouns like walad- and bint- and sayyāra(t)-; participles used participially, like kātib-; participles used nominally, like mubārā(t)-: all follow the same pattern.


What’s more, some kinds of masculine broken plurals also follow the sālim regular singular pattern of declension. Thus, the masculine word kuttāb (“(male) writers”), which is the broken plural of the word kātib- (a participle, but being used as a noun), follows the singular sālim declension. Just because a plural is formed in a broken manner does not automatically mean that its declension is also irregular.


There is also a sālim plural pattern, but this varies depending on gender. There is also a subtype of regular feminine nouns, which end in an ā, and which show slightly different endings. 

	Plural—Animate Masculine
	Definite	Indefinite	Construct
marfū‘	-ūna	-ūna	-ū
manṣūb	-īna	-īna	-ī
majrūr	-īna	-īna	-ī

This is the pattern that would be followed by the participle kātib- used participially (to describe a group of males that are currently engaged in a process of writing).

	Plural—Feminine			Plural—Long ā Feminine
	Definite	Indefinite	Construct	Definite	Indefinite	Construct
marfū‘	-ātu	-ātun	-ātu	-ayātu	-ayātun	-ayātu
manṣūb	-āti	-ātin	-āti	-ayāti	-ayātin	-ayātu
majrūr	-āti	-ātin	-āti	-ayāti	-ayātin	-ayāti

For example, the word sayyārat- in the singular declines as sayyār-āt- in the plural. The feminine ā word mubārā(t)- declines as mubār-ayāt-, etc.


More to follow on the “irregular” nominals.