Learn Italian: I pedoni devono essere prudenti quando attraversano. - Pedestrians must be cautious when they cross.

The word bisogna is strictly impersonal, meaning it translates to "one must" or "it is necessary to" and cannot take a specific subject. Because this sentence names exactly who must be cautious (i pedoni - the pedestrians), we must use a conjugated form of the verb dovere (devono) instead.

How could we change this sentence to actually use bisogna?

You would have to make the sentence impersonal and drop the specific subject ("the pedestrians"). It would become: Bisogna essere prudenti quando si attraversa (One must be cautious when crossing).

Why does the adjective prudenti end in -i here?

Prudenti is the plural of prudente (cautious). In Italian, adjectives that end in -e in the singular don't change based on gender—they work for both masculine and feminine nouns. However, they always change to -i in the plural. Here, it correctly agrees with the plural noun i pedoni.

What is the singular form of i pedoni?