Questions & Answers about Hamulce są sprawne.
Hamulce is the plural nominative form of hamulec, meaning brakes or the brakes.
In Hamulce są sprawne, hamulce is the subject of the sentence, so it appears in the nominative case.
- singular: hamulec = brake
- plural: hamulce = brakes
Są is the 3rd person plural form of the verb być (to be) in the present tense.
Because hamulce is plural, Polish uses the plural verb:
- hamulec jest sprawny = the brake is functional
- hamulce są sprawne = the brakes are functional
So są simply agrees with the plural subject.
The adjective has to agree with the noun in number, gender, and case.
Since hamulce is:
the adjective takes the form sprawne.
Compare:
- hamulec jest sprawny = the brake is functional
- hamulce są sprawne = the brakes are functional
This is normal adjective agreement in Polish.