Questions & Answers about Poliția îl poate aresta mâine.
Because Romanian usually puts the definite article at the end of the noun.
- poliție = police
- poliția = the police
So the final -a is the definite article here.
In this sentence, poliția is grammatically singular. Romanian often treats the police as a single institution, so the verb is singular too:
- Poliția poate... = The police can...
If you want to talk about the police officers as individual people, Romanian often uses polițiștii = the police officers, which is plural.