How to say "former" in Japanese

• 旧きゅうJLPT N3approx.Common
  prefixCovers 'former' in the 'ex-' sense: it goes before a noun to mark something the person or place used to have or be, now replaced by a current one.
  官僚かんりょうは旧きゅう法規ほうきの改正かいせいに関かんして、成り行なりゆきを見守みまもっています。↗

  Bureaucrats are testing the waters over revising old regulations.
• 前ぜんJLPT N1approx.Common
  noun (prefix)For 'former' in the sense 'last, immediately preceding': the holder of a title or position just before the current one. It points only one step back, not to something long past.
  前ぜん学期がっきは成績せいせきがよかった。↗

  I had a good report last term.
• 前任ぜんにんCommon
  no-adjectiveRestricted to people and posts: the former incumbent of a position, i.e. one's predecessor. If 'former' refers to the previous holder of the job you now hold, this is the word.
• 従前じゅうぜんCommon
  no-adjectiveCovers 'former' as in 'the former state of affairs': it looks back at circumstances, conditions, or arrangements as they were before a change, rather than at a former holder of a position.
  もっとも重要じゅうような点てんは、エメットの理論りろんが物理学ぶつりがくの従前じゅうぜんの理論りろんと矛盾むじゅんしないということである。↗

  It is that Emmet's theory is compatible with previous theories in physics that is of most significance.
• かつてJLPT N1approx.Common
  adverb, no-adjectiveAn adverb meaning 'once, formerly': it states that something was the case in the past, rather than marking a noun as ex-something. Usually written in kana alone.
  一般いっぱんに日本人にほんじんは、自分じぶんたちがかつてより暮らし向くらしむきがよくなったと考かんがえている。↗

  The Japanese at large consider themselves better off than they used to be.

Choose 旧 for 'ex-' style former, 前 for the immediately preceding holder of a title, 前任 for a former incumbent, 従前 for previous circumstances, and 「かつて」 when saying something was formerly the case.

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

• 旧きゅうold
• 前ぜんlast (i.e. immediately preceding)
• 前任ぜんにんformer (incumbent)
• 従前じゅうぜんprevious
• かつてonce
• 先せんformer
• 元もとformer
• 改めあらためformer (e.g. name)
• 先さきprevious
• あがりex- (e.g. ex-bureaucrat)
• 前まえprevious (e.g. page)
• 院いんformer (esp. of emperors, daimyos, etc.)