DEFINITE ARTICLE

Definite article
In Arabic, the definite article is

اَلْ

which is prefixed to nouns
For example:
ولدٌ : الولد boy : the boy
كتاب ٌ : الكتاب book : the book
بنتٌ : البنت girl : the girl
طبيبٌ : الطبيب doctor : the doctor
معلمٌ : المعلم teacher : the teacher
رجلٌ : الرجل man : the man
شمسٌ : الشمس sun : the sun
بيت ٌ : البيت house : the house
So in Arabic there is no indefinite article like a , an in English , however there is always a double vowel at the end of the indefinite noun above or below the last letter depending on the position of the word in the sentence
The double vowel is called tanween

تنوين

معلم ٌ ، معلم ٍ ، معلماً

So, what is definiteness ??
A word is considered definite when it refers to something specific and an indefinite becomes definite by adding (al) in the beginning but what if the noun is specific and doesn’t need (al)
For example : proper names like Sarah or Mohamed we cant say the Sarah , so every noun refers to someone or something specific its considered definite
In Arabic, there are seven kinds of definite cases :

1) When the definite article (al) is added to the noun
السيارة ، الحصان ، الكتاب

2) Proper nouns
سارة ، أوباما ، محمد

3) Demonstrative pronouns

هذا ، هذه

4) Pronouns
هو ، هي ، هم ، هما

5)relative pronouns :who, which ,that
الذي ، التي ، اللتان

6)when someone is called out to
يا ولد hey boy

7) When a noun is followed by a definite noun
كتاب سارة : Sarah's book
كتاب الولد : the boy's book
So (kitab) here becomes definite becomes we know which book is it ,or whom does it belong to