How to say "regular" in Japanese

• 普通ふつうJLPT N4approx.Common
  no-adjective, na-adjectiveThe everyday sense of 'regular' as in ordinary or usual — nothing special or out of the ordinary. Fits regular sizes, regular routines, or the regular train that stops at every station.
  日曜日にちようびは私にとって普通ふつうの日ひではない。↗

  Sunday is not an ordinary day to me.
• 正せいJLPT N3approx.Common
  no-adjectiveMatched to 'regular' through its sense of 'true, correct' in logical contexts. On its own it is seldom the word you want for 'regular' — it mostly works as a building block inside other words.
• 正式せいしきJLPT N3approx.Common
  na-adjective, no-adjectiveCovers 'regular' in the sense of formal or official — the proper, sanctioned way of doing something. Think of official procedures, formal applications, or doing things by the book.
  彼女かのじょの服装ふくそうは正式せいしきなパーティーでは場違ばちがいだった。↗

  Her clothes were out of place at a formal party.
• 正常せいじょうJLPT N1approx.Common
  na-adjective, nounCovers 'regular' as a state of being normal — functioning as it should, with nothing abnormal. Typical of health checks, machine readouts, or reporting that a system is operating normally.
  赤ん坊あかんぼうは正常せいじょうな発育はついくを示しめした。↗

  The baby showed a normal development.
• 正規せいきJLPT N1approx.Common
  no-adjective, na-adjectiveThe closest word for 'regular' meaning official, legitimate, or conforming to the rule — regular routes, regular members, regular procedures, as opposed to irregular or exceptional ones. It often implies being fully qualified or above board.

Choose 普通 for the everyday 'ordinary, usual' sense, 正常 for a normal state, 正式 for formal or official matters, 正規 for regular in the official or legitimate sense, and treat 正 as mainly a building block meaning 'true'.

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

• 普通ふつうnormal
• 正せい(logical) true
• 正式せいしきformal
• 正常せいじょうnormal
• 正規せいきregular
• レギュラーregular
• 定例ていれいregular
• 常任じょうにんstanding
• 整然せいぜんorderly
• 定期的ていきてきperiodic
• 規則的きそくてきsystematic
• おなじみfamiliar
• 通常つうじょうusual
• 日常にちじょうeveryday
• 几帳面きちょうめんmethodical
• 平素へいそusual
• 正則せいそくcorrect
• 定常ていじょうregular
• 規則正しいきそくただしいregular
• 行きつけいきつけregular
• なじみ客なじみきゃくregular (customer)
• 本式ほんしきformal (way)
• 合式ごうしきformal
• かかりつけfamily (doctor, etc.)
• 来付けきつけfamiliar
• 判で押したようはんでおしたようstereotyped
• お決まりおきまりstandard
• 定期ていきregular
• 常備じょうびstanding
• 買い付けかいつけ(one's) usual (store, supplier, etc.)
• 何気ないなにげないordinary
• いつもusual
• 定じょうregular
• 本ほんreal