What is the difference between "病気になる", "空く", "独立する", "潤む", "かじかむ"?

"病気になる" means "to become sick; to get ill", "空く" means "to become empty, to become available, to be vacant (intransitive)", "独立する" means "to become independent; to stand alone", "潤む" means "to become wet, to get teary, to blur (due to moisture)", "かじかむ" means "to become numb with cold; to be benumbed with cold (e.g. hands)".

Quintuple VS

Synonym Boundary: "病気になる", "空く", "独立する", "潤む", "かじかむ"

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

Japanese Option A

病気になる

びょうきになる (byōki ni naru)

N4 / CEFR

Japanese Option B

空く

あく (aku)

N3 / CEFR

Japanese Option C

独立する

どくりつする (dokuritsusuru)

N3 / CEFR

Japanese Option D

潤む

うるむ (urumu)

N2 / CEFR

Japanese Option E

かじかむ

かじかむ (kajikamu)

N2 / CEFR

Quintuple VS Nuance Contrast & Social Differences

When expressing "become" in Japanese, you must carefully distinguish between "病気になる", "空く", "独立する", "潤む", "かじかむ" based on context.

病気になる (びょうきになる (byōki ni naru) - Level: N4): Maps to "to become sick; to get ill" and is used when 「病気」は名詞で、「〜になる」は状態の変化を表す動詞です。健康な状態から病気の状態へ変わることを指します。.
空く (あく (aku) - Level: N3): Maps to "to become empty, to become available, to be vacant (intransitive)" and is used when Intransitive verb. Used for spaces becoming empty.
独立する (どくりつする (dokuritsusuru) - Level: N3): Maps to "to become independent; to stand alone" and is used when Used when a country gains sovereignty, an individual becomes self-reliant and lives apart from their family, or an organization/unit operates autonomously..
潤む (うるむ (urumu) - Level: N2): Maps to "to become wet, to get teary, to blur (due to moisture)" and is used when Typically refers to eyes getting wet with tears, or a surface becoming moist. 涙や露などでしっとり濡れる。.
かじかむ (かじかむ (kajikamu) - Level: N2): Maps to "to become numb with cold; to be benumbed with cold (e.g. hands)" and is used when Specifically describes the sensation of hands or fingers becoming stiff and difficult to move due to cold. It implies the cold has made them numb or clumsy..

Mixing these up can easily lead to unnatural translations. Refer to the bilingual context cards below to master the boundaries!

Context for "病気になる"

熱があって、病気になりました。

I had a fever and became sick.

Context for "空く"

席が空いたら、座ってください。

Please sit down when a seat becomes available.

Context for "独立する"

彼は大学を卒業後、実家から独立した。

After graduating from university, he became independent from his parents' home.

Context for "潤む"

感動的な話を聞いて、彼女の目が潤んだ。

Hearing the moving story, her eyes welled up with tears.

Context for "かじかむ"

寒さで指がかじかんで、うまく字が書けない。

My fingers are numb with cold, so I can't write well.

Synonym Mastery Challenge

Which Japanese word perfectly fits this blank space?

Fill in the blank: "熱があって、病気になりました。" (Meaning: "I had a fever and became sick.")

🎉 Correct Answer!

Remember: "病気になる" is correct here because it represents "to become sick; to get ill" in the context: "I had a fever and became sick.".