"Paris is a crowded French city."
Translation:باريس مَدينة فَرَنْسِيّة مُزْدَحِمة.
First, taking things in English: The adjective which is most relevant comes before the noun which it describes:
- Crowded (French city).
- French (crowded city).
In the first, you are describing a French city (from various French cities) to be crowded. In the second, you are describing some crowded city to be French (while others might not be so, right?). The order of the adjectives plays a role in the logic and the facts you are trying to represent.
Same thing with Arabic. However, in Arabic, adjectives come AFTER the noun they describe. Thus, the most relevant adjective comes AFTER the noun. Since we have, in English, a crowded French city, then in Arabic that literally would be city/French/crowded - مدينة فرنسية مزدحمة.
Paris: subject, the thing we want to talk about. Hence it is first here.
(a) city: here, we are telling the nature of Paris. In other words, if I say باريس مدينة this would translate to (Paris is a city) and NOT (Paris city) or (the city of paris).
The last 2 words are adjectives describing "city" مدينة to complete the meaning. And since مدينة (city) is feminine, these two adjectives come in feminine form.