How to say "impetus" in Japanese

Choosing the right word
  • 衝動しょうどうCommon
    nounCovers impetus as an inner urge — a psychological push from within that drives a person to act. Fits when the driving force is emotional rather than an outside trigger or physical momentum.
    彼かれは衝動しょうどうに駆かられた。↗
    He was borne away by an impulse.
  • 余勢よせいCommon
    nounImpetus as surplus momentum left over from a previous action or movement, which carries you forward into what comes next — the force of one effort or success spilling over into another.
  • きっかけJLPT N2approx.Common
    nounImpetus as the trigger or cue that sets something in motion — the initial occasion for starting, not the force that sustains it. Suits 'the impetus for' a decision or change.
    彼かれ等らは彼かれに逃にげるきっかけを与あたえた。↗
    They gave him a chance to escape.
  • 刺激しげきJLPT N3approx.Common
    noun, suru verb, transitive verbImpetus as an outside stimulus or spur — something that provokes or energizes action, growth, or change. Fits when the push comes from an external source acting on someone, as a spur to greater effort.
    昇進しょうしんがより一層いっそう働はたらく刺激しげきとなった。↗
    Promotion was an incentive to harder work.
  • はずみCommon
    nounImpetus as the momentum of a movement itself — the force built up while something is in motion, which carries the action along. Also covers doing something on the sudden bounce of the moment.
    ドル安やすは輸出ゆしゅつにはずみをつけています。↗
    The cheap dollar is charging up exports.

Choose 衝動 for an inner urge, 刺激 for an external stimulus or spur, 「きっかけ」 for the trigger that starts something, 余勢 for momentum carried over from a previous action, and 「はずみ」 for the momentum of a movement itself.

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

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JLPT vocabulary levels are community estimates, not official (no official lists have been published since the 2010 revision).

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