A diacritic (ـْ) is used in Arabic to mark the absence of vowels.
The “Sukoon” is a small circle over the letter.
It is put over a letter when no sound should be pronounced after the letter. It indicates that there is no vowel.
Sukoon is sometimes NOT placed above the letter at the end of the words.
GRAMMATICAL CASES. TANWEEN.
There are three grammatical cases in Arabic – nominative, genitive and accusative but they do not always reflect the same cases in other languages.
NOMINATIVE – it is called raf – it is indicated by DAMMA OVER THE FINAL CONSONANT. It is usually used to indicate to a noun. Will be studied in detail later.
GENITIVE– it is called jarr – it is indicated by KASRA UNDER THE FINAL CONSONANT. It is usually used after preposition or to express possession. Will be studied in detail later.
ACCUSATIVE – it is called nașb – it is indicated by FATḤA OVER THE FINAL CONSONANT. It is usually used with adverbs, objectives and verbs. Will be studied in detail later.
TANWEEN.
The name of tanween is derived from the letter noon because tanween (تنــوين) sounds like noon (n) (ن) at the end of words. Grammatically tanween indicates indefinite, singular and plural nouns, but never dual nouns. It appears only at the end of words. Tanween marks are three as shown below.
Tanween damma: or double damma above the last letter is pronounced like un.
Tanween fatha: or double fatḥa above alif as the last letter is pronounced an
Tanween kasra: or double kasra below the last letter is pronounced like in