How to say "substitute" in Japanese

• 代わりかわりJLPT N4approx.Common
  no-adjectiveThe general noun for a substitute or replacement — one person or thing used or acting in place of another. Covers both 'instead of' and 'on someone's behalf'.
  自分じぶんで行いく代かわりに手紙てがみを送おくりました。↗

  Instead of going myself, I sent a letter.
• サブCommon
  nounThe loanword 'sub': a reserve or backup standing in for the main person or thing, as with a substitute player on a team.
• 入れ替えるいれかえるCommon
  ichidan verb, transitive verbThe verb for the act of substituting: replacing or switching one thing out for another. Use this when 'substitute' is something you do, not a person or thing that serves as one.
  窓まどを開あけてむしむしするこの部屋へやの空気くうきを入れ替いれかえて下ください。↗

  Will you open the window and air out this stuffy room?
• 身代わりみがわりCommon
  nounSubstitution for a person: standing in someone's place, often to take what would otherwise fall on them — blame, punishment, harm — which is also the 'scapegoat' sense.
  その司祭しさいは病気びょうきの男おとこの身代みがわりになった。↗

  The priest took the sick man's place.
• 替え玉かえだまCommon
  nounA stand-in, double, or proxy: a person who takes another's place or appears in their stead, sometimes passing as the real person. This is about people, not things.
  警察けいさつが追おっていたのは替え玉かえだまで、その間あいだに真犯人しんはんにんを逃のがしてしまった。↗

  The police followed a red herring while they let the true criminal escape.

Use 「代わり」 for the general 'in place of' sense, 「サブ」 for a casual sub or backup, 「入れ替える」 for the act of swapping one thing for another, 「身代わり」 for standing in for a person, and 「替え玉」 for a double or proxy.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 代わりかわりsubstitute
• サブsub
• 入れ替えるいれかえるto replace
• 身代わりみがわりsubstitution (for someone else)
• 替え玉かえだまstand-in
• 代役だいやくsubstitute (actor)
• 代人だいにんsubstitute
• 代理人だいりにんproxy
• 副ふくassistant
• うつすto transfer (to a different place, group, etc.)
• 代物だいぶつsubstitute
• 代用品だいようひんsubstitute
• サブスティテュートsubstitute
• 代用語だいようごsubstitute
• すり替えるすりかえるto switch (secretly)
• 置き換えおきかえreplacement
• 掛け替えるかけかえるto replace (a picture, sign, hanging scroll, etc.)
• 代理者だいりしゃproxy
• 補欠選手ほけつせんしゅspare player
• 替えかえsubstitute
• 代替だいたいalternative
• 取り替えるとりかえるto replace
• 補欠ほけつsubstitute
• 代走だいそうsubstitute
• 替えるかえるto substitute (person, staff member, player, etc.)
• 代理だいりproxy
• 置き換えるおきかえるto replace
• 交換品こうかんひんsubstitute
• 振るふるto replace