As iron sharpens iron, so people can improve each other.
Proverb 27:17 NCV

Proverbs 27:17 (Amplified Bible) “Iron sharpens iron; so a man sharpens the countenance of his friend [to show rage or worthy.” purpose].

Proverbs 27:17 (NLT) ” As iron sharpens iron, so a friend sharpens a friend.”

#1 can
#2 rage or worthy
#3 friend

Whom does it depend on? You or the other?

Matthew Henry says, “We are cautioned to take heed whom we converse with. And directed to have in view, in conversation, to make one another wiser and better.” (Pr 27:18)