Cases and case endings are used in Classical Arabic (used in the Quran), as well as Modern Standard Arabic (MSA) for poetry, media broadcasts, and other formal situations. Case endings affect the pronunciation of words (nouns and adjectives). Case endings are normally omitted in informal conversation and writings, and regional dialects or Arabic.

A double damma, double kasra, or double fatha indicates that a noun is indefinite (e.g. “a book”) versus definite (”the book”). Which case ending used depends grammatical position or function of a word.

Nominative (مرفوع - marfua’) - Indicated with a damma (”u” or “un”) at the end of a word, such as كتابُُ (kitabun) which means “a book”. Nouns that are the subject of a sentence are in the nominative case. Such as كتابُُ على الطاولة (kitabun a’la al tawila) which is “A book is on the table.”

Accusative (منصوب - mansub) - Indicated with a fatha (”a” or “an”), such as أقرُ كتابََ (iqaru kitaban) - “I am reading a book.” The accusative case is used for nouns that are the object of a verb. Adverbs are also marked in the accusative case with a double fatha.

Genitive (مجرور - majrur) - Indicated with a kasra (”i” or “in”), such as القميصُ في درجِ (al-qamisu fi durjin) - “The shirt is in a drawer.” The genitive case is used for nouns that are the object of a preposition.