This is the 200th most frequent Polish word.
powinien
"Powinien" means "should" or "ought to" in English.
'Powinien' is used to express an obligation or recommendation here.
Janek powinien odrobić pracę domową.
Janek should do his homework.
'Powinienem' is the first-person singular form, indicating a self-directed obligation or suggestion.
Powinienem iść już do domu.
I should go home already.
'Powinienem' here forms a question, inquiring about the appropriateness or necessity of knowing additional information.