Learn Italian: Nessuno conosce il nuovo candidato. - Nobody knows the new candidate.

Because the sentence is about knowing a person. We use conoscere when talking about being familiar with people, places, or things. We use sapere (where sa comes from) for knowing facts or knowing how to do something.

Why isn't there a non in this sentence? Doesn't Italian use double negatives?

Italian does use double negatives, but only when negative words like nessuno (nobody) come after the verb. Because nessuno is at the very beginning of this sentence, acting as the subject, we drop the non.

Is nessuno always treated as singular?

Yes! Just like the English word nobody, nessuno takes the third-person singular form of the verb. That is why we use conosce instead of a plural form like conoscono.

Why is the adjective nuovo placed before the noun candidato?

While most Italian adjectives go after the noun, there is a small group of common, everyday adjectives that usually go before it. Nuovo (new) is one of these, along with words like bello (beautiful), buono (good), and vecchio (old).