Nuance & Usage
効果 describes the result or impact of an action, treatment, or method. 効果がある (kouka ga aru) means 'to be effective,' and 効果的 (koukateki) is the na-adjective form meaning 'effective.' 副作用 (fukusayou — side effects) is a related medical term. 効果を発揮する (kouka wo hakki suru) means 'to demonstrate its effect.' It is commonly used in contexts like medicine, education, and business strategies.
Common Mistakes
Learners sometimes confuse 効果 with 結果 (kekka — result/outcome). 効果 specifically refers to the impact or effectiveness of something, while 結果 is a broader term for any result or outcome. Don't say 効果を出す — instead say 効果がある or 効果を発揮する. Also, 効果的 (effective) is a na-adjective: use 効果的な方法, not 効果的い方法.
Example Sentences (3)
この薬は風邪に効果がある。
このくすりはかぜにこうかがある。
This medicine is effective for colds.
新しいマーケティング戦略の効果を分析した。
あたらしいまーけてぃんぐせんりゃくのこうかをぶんせきした。
We analyzed the effectiveness of the new marketing strategy.
毎日の運動が健康に大きな効果をもたらす。
まいにちのうんどうがけんこうにおおきなこうかをもたらす。
Daily exercise brings significant health benefits.
Quick Quiz
Quick Quiz
N24 questionsTest your knowledge of 効果 with 4 different question types.
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