El cartero es menos importante porque usamos

travel to mexico,

you would sell things that you don't use anymore.

their's 2 things you could put in your spanish assignment.

corras is the only one that is informal but doesn't follow the suffix rule. correr is the verb. corre is the formal verb form. corra would be used as the formal is corre ended with an a.

your best bet would be corras, it's the only one that is informal but is still wrong