Quadruple VS
Synonym Boundary: "開く", "開通する", "打ち解ける", "散開星団"
All represent the core concept "open", but require precise selection.
Japanese Option A
開く
あく (aku)
N4 / CEFR
Japanese Option B
開通する
かいつうする (kaitsū suru)
N3 / CEFR
Japanese Option C
打ち解ける
うちとける (uchitokeru)
N2 / CEFR
Japanese Option D
散開星団
さんかいせいだん (sankaiseidan)
C2 / CEFR
Quadruple VS Nuance Contrast & Social Differences
When expressing "open" in Japanese, you must carefully distinguish between "開く", "開通する", "打ち解ける", "散開星団" based on context.
- 開く (あく (aku) - Level: N4): Maps to "to open (intransitive)" and is used when Intransitive verb. Used when something opens on its own or is opened by an unspecified agent.
- 開通する (かいつうする (kaitsū suru) - Level: N3): Maps to "to open (for traffic), to be completed (e.g., a tunnel, bridge, line)" and is used when Used for infrastructure like roads, railways, tunnels, or new services becoming available for public use. It's an intransitive verb..
- 打ち解ける (うちとける (uchitokeru) - Level: N2): Maps to "to open one's heart, to become friendly, to relax" and is used when To become less reserved, more relaxed and informal with someone, moving from a formal or tense state to a more comfortable and open one. Often used with the particle 「に」..
- 散開星団 (さんかいせいだん (sankaiseidan) - Level: C2): Maps to "Open cluster" and is used when Essential structural term in CEFR C2 vocabulary syllabus..
Context for "開く"
ドアが自動的に開きます。
The door opens automatically.
Context for "開通する"
新しい高速道路が来月開通する予定だ。
The new highway is scheduled to open next month.
Context for "打ち解ける"
彼はどんな人ともすぐに打ち解けることができる。
He can quickly become friendly with anyone.
Context for "散開星団"
私は散開星団に興味があります。
I am interested in Open cluster.
Synonym Mastery Challenge
Which Japanese word perfectly fits this blank space?
Fill in the blank: "ドアが自動的に開きます。" (Meaning: "The door opens automatically.")
🎉 Correct Answer!
Remember: "開く" is correct here because it represents "to open (intransitive)" in the context: "The door opens automatically.".