The referee must be fair to both teams.
- Sędzia musi być bezstronny.
An artist must have an eye for colour.
- Artysta musi mieć oko do kolorów.
He has to speak English.
- On musi mówić po angielsku.
An artist has to have a color-sensitive eye.
- Artysta musi mieć oko do kolorów.