"The professor's newspaper is blue."
Translation:صَحيفة اَلْأُسْتاذ زَرْقاء.
صحيفة الأستاذ = newspaper of the professor
الصحيفة الأستاذ (this one actually does not have a real meaning)
The first example is a correct idafa-construction (genitiv construction) where first noun takes indefinite mode and the second one takes a definite mode.
Can it be that it is a rule and with the genitive we only have to use the indefinite article?
If you remember in one of my posts in the forum, I've explained how the definite artilce "AL" plays a major role in defining the nature of relation between 2 words. If we are talking genitive (of-relationship) then the second one in the compound is the one to get "AL" (if the whole compound is defined).
If the compound is not to be defined, then no word gets definite article but one must make sure that the second word has Kasrah (or Tanwin bil Kasr -in if indefinite).
- صحيفة الأستاذِ (CaHífatul-UstaTHi) *The newspaper of the professor.
- صحيفةُ أستاذٍ (CaHífatu UstaThin) a newspaper of a professor