Learn Polish: Czy to dobra decyzja? Trudno powiedzieć. - Is it a good decision? Hard to say.

You can absolutely say Czy to jest dobra decyzja?, but Polish often drops the verb być (to be) when using to to point something out or identify it. The pattern "To + [adjective] + [noun]" frequently skips the verb in everyday speech to sound more natural and concise.

Why is it trudno (an adverb) and not trudne (an adjective) when translating "Hard to say"?

In Polish, impersonal phrases—sentences where there is no specific "who" or "what" acting as the subject—require an adverb. Since there is no specific noun being described as "hard", you must use the adverb trudno combined with the infinitive powiedzieć (to say).

Why use the perfective verb powiedzieć instead of the imperfective mówić?

Trudno powiedzieć is a very common fixed phrase meaning "it's hard to tell" or "it's hard to give a definitive answer." You use the perfective powiedzieć because you are referring to the completion of an action—giving a single, final answer—rather than the ongoing process of talking (mówić).