Learn Polish: Ten ekran jest rozbity i nie działa. - This screen is smashed and does not work.

It comes from the perfective verb rozbić (to smash or break). For verbs with a short stem ending in a vowel plus -ć (like -bić, -pić, or -myć), we form the passive adjectival participle by dropping the -ć and adding the suffix -ty. Because ekran is a masculine noun in the nominative case, we use the standard masculine singular ending, giving us rozbity.

Could we use the suffix -ny or -ony instead of -ty for this verb?

No, the choice of suffix depends strictly on the verb's infinitive ending. Verbs ending in -ać usually take -ny (like napisać becoming napisany), and verbs ending in -ić or -eć often take -ony (like zrobić becoming zrobiony). Verbs ending in -bić belong to a specific group that always takes the -ty suffix.

Does rozbity act like a verb or an adjective here?

Even though it is formed from a verb, it acts exactly like an adjective in this sentence. Passive adjectival participles describe the state of a noun after an action has happened to it. Just like any normal adjective, rozbity changes its ending to match the noun it describes, which is why it takes the masculine, singular, nominative form to agree with ten ekran.

Why do we use działa for "works" instead of pracuje?