This is the 880th most frequent Polish word.
nowym
"Nowym" means "new" in the instrumental or locative case in Polish.
Here, 'nowym' is used as an adjective in the locative case, agreeing with the noun 'budynku' (building), which is also in the locative case. It describes the new state or attribute of the building.
Postanowiono otworzyć szkołę w nowym budynku.
It was decided to open the school in the new building.
In this sentence, 'nowym' is an adjective in the instrumental case, agreeing with the noun 'początkiem' (beginning), which is in the instrumental case as required by the preposition 'z' indicating an instrumental complement.
Cieszę się z nowym początkiem.
I am happy for the new beginning.
Here, 'nowym' is used in the instrumental case as an adjective describing 'nauczycielem' (teacher), following the preposition 'z'. It specifies the state or characteristic of the teacher as being 'new'.