ichidan verb, transitive verb
Only when written 替える
Used when swapping out an old or broken item for a new one of the same kind, or when changing something to a different state. Typically written 替える.
電池を新しいのに替えた。
I replaced the batteries with new ones.
カーテンを
I change the curtains to the summer ones.
ichidan verb, transitive verb
Only when written 換える
Used when exchanging one thing for another, especially money, goods, or abstract things like words. Typically written 換える.
ドルを円に換える。
I exchange dollars for yen.
ポイントを景品に換える。
I convert points into prizes.
ichidan verb, transitive verb
substitute; replace (a person)
Only when written 代える
Used when one person takes the place of another in a role, job, or position. Typically written 代える.
監督は疲れた選手を代えた。
The manager substituted the tired player.
急用で、私が彼に代わって会議に出る代わりに、彼に私の役を代えてもらった。
Due to a sudden matter, instead of me attending the meeting in his place, I had him substitute for my role.