expression, suru verb (irregular)
associate with; deal with; take notice of
Used for engaging with someone, often in a social or business context. Can imply willingness to interact or take someone seriously.
彼は誰も相手にしなかった。
He didn't associate with anyone.
あの人は
That person doesn't listen to reason, so it's better not to deal with them.
expression, suru verb (irregular)
play against; take on (a rival)
Used in competitive contexts, such as sports or games, where one faces an opponent.
See also: 相手をする
次の試合では強いチームを相手にすることになる。
We'll be playing against a strong team in the next match.