🦅 Project Eagle
Quadruple VS

Synonym Boundary: "いい", "良い", "おやすみなさい", "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

おやすみなさい

おやすみなさい (oyasuminasai)
N5 / 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", "おやすみなさい", "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」.
  • おやすみなさい (おやすみなさい (oyasuminasai) - Level: N5): Maps to "Good night" and is used when A polite farewell greeting used in the evening, especially when someone is going to bed or when parting ways late at night. A more casual version, おやすみ.
  • 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 "おやすみなさい"
父に「おやすみなさい」と言ってから寝ました。
I said "Good night" to my father before going to bed.
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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