This is the 3026th most frequent Polish word.
pewnych
"Certain" or "some" (dependent on context).
In this sentence, 'pewnych' is used to mean 'certain' or 'some,' describing a subset of acquaintances.
Miałem pewnych znajomych z uniwersytetu.
I had certain acquaintances from university.
Here, 'pewnych' implies 'some,' referring to a specific but unnamed portion of information.
Potrzebuję pewnych informacji, zanim podejmę decyzję.
I need some information before I make a decision.
In this sentence, 'pewnych' denotes 'certain,' pointing to particular situations where the condition applies.