This is the 1112th most frequent Polish word.
podstawowej
"Podstawowej" means "primary" or "basic" in English, depending on the context.
Here the word 'podstawowej' is used as an adjective in the genitive case, describing 'szkoły' (school) as 'elementary'.
Ta książka polecana jest uczniom szkoły podstawowej.
This book is recommended for elementary school students.
In this sentence, 'podstawowej' functions as an adjective in the genitive feminine singular, modifying 'matematyki' (mathematics) to mean 'basic' or 'fundamental'.
Znajomość podstawowej matematyki jest konieczna.
Knowledge of basic mathematics is necessary.
The word 'podstawowej' is used as an adjective in the genitive feminine singular to describe 'zasady' (rule), signifying a primary or fundamental characteristic.