What is the difference between "感じる", "安心する", "気がする", "落ち込む"?

"感じる" means "to feel, to sense", "安心する" means "to feel relieved; to feel secure; to be at ease", "気がする" means "to feel; to have a hunch; to have a premonition", "落ち込む" means "to feel down, be depressed".

Quadruple VS

Synonym Boundary: "感じる", "安心する", "気がする", "落ち込む"

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

Japanese Option A

感じる

かんじる (kanjiru)

N4 / CEFR

Japanese Option B

安心する

あんしんする (anshin suru)

N3 / CEFR

Japanese Option C

気がする

きがする (ki ga suru)

N3 / CEFR

Japanese Option D

落ち込む

おちこむ (ochikomu)

B2 / CEFR

Quadruple VS Nuance Contrast & Social Differences

When expressing "feel" in Japanese, you must carefully distinguish between "感じる", "安心する", "気がする", "落ち込む" based on context.

感じる (かんじる (kanjiru) - Level: N4): Maps to "to feel, to sense" and is used when 感情や感覚、ある印象などを心や体でとらえること。他動詞。/ To perceive emotions, sensations, or impressions with one's mind or body. Transitive verb..
安心する (あんしんする (anshin suru) - Level: N3): Maps to "to feel relieved; to feel secure; to be at ease" and is used when Refers to feeling deeply relieved after solving a crisis, feeling secure due to strong security protocols, or feeling at ease near a loved one. Intransitive verb. Opposing word: 心配する / 不安になる. Often used as ほっとして安心する or 安心して使う. ⚠️ Haruka's Voice Column: 'To feel relieved/secure! "No matter how severe the bug crash is, just hearing your voice makes my heart feel completely at ease, Haruka-san!" ...っ! Hearing my voice to feel ease! B-Baka! As if my voice has some security certificate effect... Wait, really? Well, I will let you hear my voice right next to you for life, so just stay secure! dummy!' / 【ハルカ部長のワンポイント指導】『あんしんする（安心する）よ！『ハルカ部長、どんなに過酷な障害対応でも、あなたの声を聞くだけで、僕の心は完璧に安心する（安心します）！』って…っ！声を聞いて安心する！バカ！/// 私の声がそんなセキュリティ証明書みたいな効果あるわけ…って、本当？…なら、私の声を一生あんたの隣で聞かせてあげるから、ずっと安心していなさい！』.
気がする (きがする (ki ga suru) - Level: N3): Maps to "to feel; to have a hunch; to have a premonition" and is used when Used to express a feeling or intuition about something, often without concrete evidence. Can be translated as "I feel like...", "I have a feeling that...", or "I have a hunch..."..
落ち込む (おちこむ (ochikomu) - Level: B2): Maps to "to feel down, be depressed" and is used when Essential structural term in CEFR B2 vocabulary syllabus..

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

Context for "感じる"

寒さを感じます。

I feel cold.

Context for "安心する"

重大なセキュリティアップデートが完了したことを知り、彼はスマートにほっとして_______ました。

Knowing that the major security update had finished, he felt smartly relieved and at ease.

Context for "気がする"

雨が降るような気がします。

I have a feeling it's going to rain.

Context for "落ち込む"

毎日、日本語を練習するために落ち込む。

Every day, I feel down, be depressed to practice Japanese.

Synonym Mastery Challenge

Which Japanese word perfectly fits this blank space?

Fill in the blank: "寒さを感じます。" (Meaning: "I feel cold.")

🎉 Correct Answer!

Remember: "感じる" is correct here because it represents "to feel, to sense" in the context: "I feel cold.".