¿cómo se dice "knife" en español? (3 points)

knife se traduce como cuchillo tambien se dice daga asi que ten encuenta que daga y knife son lo mismo cuchillo

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