This is the 806th most frequent Polish word.
naszą
"Naszą" means "our" (feminine singular instrumental form) in English.
'Naszą' is the accusative singular feminine form of 'nasz' (our), agreeing with the feminine noun 'szkołę' (school) in the accusative case due to the verb 'odwiedził' (visited).
Naszą szkołę odwiedził znany pisarz.
A famous writer visited our school.
'Naszą' is the instrumental singular feminine form of 'nasz' (our), agreeing with the feminine noun 'sprawą' in the instrumental case used with the predicate construction.
To jest naszą wspólną sprawą.
This is our common cause.
'Naszą' is the instrumental singular feminine form of 'nasz' (our), matching the feminine descriptive noun phrase 'nową nauczycielką' required by the preposition 'z' (with).