This is the 1665th most frequent Russian word.
париже
"Париже" is the prepositional case of "Париж," meaning "in Paris" in English.
In this sentence, "в Париже" (in Paris) is used to indicate the location where the speaker was during the mentioned period. "Париже" is found in its prepositional case form to suit the sentence's grammatical structure.
Я был в Париже прошлым летом.
I was in Paris last summer.
Here, "в Париже" (in Paris) refers to the location where the fashion shows are held. The prepositional case is used because this part of the statement specifies the place.
В Париже проходят модные показы.
Fashion shows take place in Paris.
In this example, "в Париже" (in Paris) describes the residence of the friend. The prepositional case is used to denote location, in accordance with the verb "живет" (lives).