Interrogatives are words used to form questions. One of the easiest ways to fare una domanda (ask a question) in Italian is to place a question mark at the end of a statement, effectively changing it into a question. When speaking, the intonation of the voice rises at the end of the sentence. For example:

Il treno è arrivato. (The train has arrived.)

Il treno è arrivato? (Has the train arrived?)