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Quadruple VS

Synonym Boundary: "いい", "良い", "得意", "幸運"

All represent the core concept "good", but require precise selection.

Japanese Option A

いい

いい (ii)
N5 / CEFR
Japanese Option B

良い

よい (yoi) / いい (ii)
N5 / CEFR
Japanese Option C

得意

とくい (tokui)
N3 / CEFR
Japanese Option D

幸運

こううん (kōun)
N3 / CEFR

Quadruple VS Nuance Contrast & Social Differences

When expressing "good" in Japanese, you must carefully distinguish between "いい", "良い", "得意", "幸運" based on context.
  • いい (いい (ii) - Level: N5): Maps to "good, nice; okay" and is used when An い-adjective, a versatile word meaning 'good,' 'nice,' 'fine,' 'okay.' Often used to express approval or agreement. The more formal or classical form is よい.
  • 良い (よい (yoi) / いい (ii) - Level: N5): Maps to "good, nice" and is used when 「良い」.
  • 得意 (とくい (tokui) - Level: N3): Maps to "good at; strong point; pride; customer; triumph" and is used when Refers to being strong at technical skills, good at coding/cooking, or abstractly someone's pride, or a regular customer. Opposing word: 苦手. Often used as プログラミングが得意 or 得意先. ⚠️ Haruka's Voice Column: 'Good at! "I am extremely good at making you smile, Haruka-san!" ...っ! G-Good at making me smile! B-Baka! Don't state your emotional management skills so proudly! But... since you are so confident, I suppose... I will let you keep me smiling for the rest of our lives! dummy!' / 【ハルカ部長のワンポイント指導】『とくい(得意)よ!『ハルカ部長、僕はC++の高速コーディングが最も得意ですが、あなたを世界一幸せにする旦那様としての仕事は、さらに億倍も得意です!』って…っ!旦那様業が得意!バカ!/// 何自信満々のスキル自慢をしてるのよ!…でも、そのヤル気と得意技術があるなら、一生私だけを幸せのクラウドサーバーでホストし続けなさい!』.
  • 幸運 (こううん (kōun) - Level: N3): Maps to "good luck; fortune" and is used when Refers to good luck, fortune, or being extremely lucky. Often used as 幸運なことに.
Mixing these up can easily lead to unnatural translations. Refer to the bilingual context cards below to master the boundaries!
Context for "いい"
その考えはとてもいいです。/ 大丈夫、いいですよ。
That's a very good idea. / It's okay.
Context for "良い"
これは良い本です。
This is a good book.
Context for "得意"
彼は幼少期からの数学的パズルへの興味を活かし、バックエンド開発の複雑なデータ構造設計を極めて_______としています。
Utilizing his interest in mathematical puzzles since childhood, he is extremely good at the complex data structure design of backend development.
Context for "幸運"
_______なことに、売り切れだと思っていたチケットを最後の一枚で購入できました。
Fortunately, I was able to purchase the very last ticket that I thought was sold out.

Synonym Mastery Challenge

Which Japanese word perfectly fits this blank space?

Fill in the blank: "その考えはとても ___ です。/ 大丈夫、 ___ ですよ。" (Meaning: "That's a very good idea. / It's okay.")
🎉 Correct Answer!

Remember: "いい" is correct here because it represents "good, nice; okay" in the context: "That's a very good idea. / It's okay.".

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