This is the 427th most frequent Polish word.
jakim
"Jakim" means "what" or "which" in instrumental case in Polish.
Here, 'jakim' functions as an interrogative pronoun to inquire about the specific city.
W jakim mieście się urodziłeś?
In which city were you born?
Here, 'jakim' is used to inquire about descriptive qualities of a person.
Jakim człowiekiem jest on według ciebie?
What kind of person is he according to you?
In this case, 'jakim' introduces an indirect question about the language.