How to say "cause" in Japanese

• 訳わけJLPT N4approx.Common
  nounGlossed 'cause', but this is really the word for 'reason' — the explanation or grounds behind something, why it is so or was done. For the cause of an accident or illness you want 原因.
  そういうわけで私はこんなに早はやく帰かえって来きたのです。↗

  That's why I came back so soon.
• 原因げんいんJLPT N4approx.Common
  noun, suru verb, intransitive verbThe default noun for 'cause': the factor or event that brought something about — the cause of an accident, an illness, a failure. Also covers the senses 'origin' and 'source'.
  それで事故じこの原因げんいんが分わかった。↗

  That accounts for the accident.
• 由よしCommon
  nounDespite the gloss 'cause', seldom the word you want: 由 is really about reason and significance — the why or the point of something. For a cause in the noun sense, use 原因.
• 生ずるしょうずるJLPT N2approx.Common
  ichidan verb (-zuru), transitive verbVerb 'to cause' in the sense of producing or giving rise to a result — a change, a difference, trouble. The nuance is the result coming into being; for provoking trouble, 引き起こす is the usual choice.
• 引き起こすひきおこすJLPT N1approx.Common
  godan verb, transitive verbThe usual verb for causing something, especially trouble: accidents, problems, disputes. Where 生ずる presents a result as arising, 引き起こす stresses the act of bringing it about.
  彼かれの不注意ふちゅういな運転うんてんが事故じこを引き起ひきおこした。↗

  His careless driving caused the accident.

For the noun, 原因 is the default; 訳 and 由 are really about reasons and seldom fit. For the verb, use 「引き起こす」 for causing trouble; 「生ずる」 is to produce or give rise to something.

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

• 訳わけreason
• 原因げんいんcause
• 由よしreason
• 生ずるしょうずるto produce
• 引き起こすひきおこすto cause
• 及ぼすおよぼすto exert (influence)
• 起こりおこりsource
• 巻き起こすまきおこすto create (a sensation)
• 因いんcause
• 事由じゆうreason
• 生じるしょうじるto produce
• 根源こんげんroot
• 大本おおもとroot
• 種くさcause
• ゆえreason
• きたすto cause
• 因由いんゆcause
• いわれreason
• 本源ほんげんorigin
• 惹起じゃっきbringing about
• 成因せいいんorigin
• 原由げんゆreason
• 因をなすいんをなすto give rise to
• 来由らいゆorigin
• 元もとcause
• 起こすおこすto cause
• もたらすto bring about
• 起因きいんcause
• 契機けいきtrigger
• 火種ひだねcause (of disturbance, conflict, etc.)
• 口火くちびcause (of a war, argument, revolt, etc.)
• 誘い水さそいみずcause
• 旗印はたじるしbanner (e.g. of democracy)
• 立てるたてるto make (a noise)
• 根ねroot (of all evil, etc.)
• 所為しょいcause
• 醸すかもすto cause
• 源頭げんとうcause
• 縁由えんゆorigin
• かけるto cause (someone inconvenience, trouble, etc.)
• 与えるあたえるto cause
• たねcause
• 招くまねくto bring on oneself