lock
The word 'serratura' in Italian translates to 'lock' in English. It is used to secure doors, windows, and other openings to prevent unauthorized access. It can also refer to the mechanism that secures something, such as a lock on a suitcase or a padlock on a gate. In some cases, 'serratura' can also refer to a lock of hair, as in a curl or a lock of hair that has been cut off.
The key is in the lock
This phrase implies that the key is in the lock which could be through intention or an accident. It is usually said when one is confirming the location of the key, usually because it is misplaced or lost.
The lock is broken
This phrase is usually said when one wants to confirm or inform others that the lock is broken and may not function as expected. It definitely suggests that there is a problem with the lock's mechanism.
I can't open it without the lock
This phrase means that the speaker cannot open something, likely a door or a box, without the lock. This could be because the lock is integral to the item opening or because it is locked and they do not have the key.