Questions & Answers about Mój krewny nocował u mnie.
The word krewny means relative, but it has an adjective ending. Is it a noun or an adjective?
It is a substantivized adjective, which means it functions entirely as a noun in the sentence but declines exactly like an adjective. Because it takes adjective endings, a female relative would be krewna, and the plural relatives would be krewni.
How would this sentence change if the relative was a woman?
You would change the possessive pronoun, the substantivized adjective, and the verb to their feminine forms. The sentence would become: Moja krewna nocowała u mnie.
I recognize the word noc (night) inside nocował. Are they related?
Yes! The verb nocować is formed directly from the noun noc. It literally means to spend the night or to stay overnight. Adding the suffix -ować to a noun is a very common way to create verbs in Polish.
Why do we use mnie after the preposition u?
The preposition u (at, by, or at the house of) always requires the genitive case. The genitive form of ja (I) is mnie. You will see this same structure in phrases like u ciebie (at your place) or u niego (at his place).