BismiLlahir Rahmanir Raheem
The Arabic article “ال” signifies that a noun is definite. Another form of definiteness is the possessive case. When a noun is possessed, it is called مضاف and is written before its possessor without ‘ال’ or tanween and the possessor( مضاف إليه ) ends in the genitive case with ‘ال’ or tanween.
An illustration of the above is the expression ‘بقرة الفلاح’ . Here, the word ‘بقرة’ (baqorotu) which should take the normal ending ‘un’ losts its tanween and becomes definite by position while the possessor which must be definite in itself takes an ‘ ال’ and ends with a kesro. Hence, if the possessor is a proper noun such as حامد، the kesro becomes 2 (ie tanween).
More examples are given below: