Learn Italian: Perché non allacci mai la cintura? - Why do you never fasten your seatbelt?

In Italian, to say "never", you usually use a double negative structure: non + [verb] + mai. It literally translates to "you do not fasten ever". If you put mai after the verb, you almost always need non before it!

The translation says "your seatbelt", but the Italian says la cintura (the seatbelt). Why isn't it la tua cintura?

In Italian, when it's obvious who an item belongs to—especially for clothes, body parts, or things you are wearing like a seatbelt—you usually just use the definite article (la, il, etc.) instead of a possessive word like tua. Since the verb is in the "tu" (you) form (allacci), it's already clear whose seatbelt it is!

The dictionary form is allacciare. Why isn't the "you" form spelled with a double "i" like allaccii?

For verbs ending in -ciare or -giare (like allacciare or mangiare), you drop the extra i when forming the "tu" form. This is to avoid having an awkward double i at the end. So, it becomes just allacci.

This lesson is about bisogna. How would I use that here to say "One must fasten the seatbelt"?