Translation guide
Describes an action or attitude that lacks full effort, enthusiasm, or commitment. Japanese expresses this through adjectives, adverbs, and set phrases that convey doing something without sincerity or energy.
Describe an action or attempt that is not done with full energy or commitment.
The most common and versatile way to say 'half-hearted'. It literally means 'halfway, incomplete' and can describe efforts, attitudes, or results.
彼は中途半端な態度で仕事をしている。
He does his work with a half-hearted attitude.
中途半端な気持ちで始めると失敗する。
If you start with a half-hearted feeling, you'll fail.
Means doing something in a sloppy, half-hearted, or irresponsible manner. Often implies lack of care.
いい加減に返事をしないでください。
Don't give a half-hearted reply.
Means 'half-baked' or 'superficial'. Stronger than 中途半端, often used for knowledge or skills.
生半可な知識で挑戦するのは危険だ。
It's dangerous to take on a challenge with half-hearted knowledge.
Express that an apology, compliment, or gesture is not heartfelt.
Literally 'the heart is not put into it'. Used for insincere words or actions.
彼の謝罪は心がこもっていなかった。
His apology was half-hearted.
Means 'superficial' or 'only on the surface'. Describes words or actions that lack depth.
うわべだけの励ましは逆効果だ。
Half-hearted encouragement can backfire.
Describe an action done because one has to, not because one wants to.
Means 'reluctantly' or 'grudgingly'. Conveys doing something with visible lack of enthusiasm.
彼はしぶしぶ承諾した。
He gave a half-hearted consent.
Means 'unwillingly'. Often used for children or informal situations.
中途半端 focuses on incompleteness or lack of full commitment, while いい加減 implies irresponsibility or carelessness. 中途半端 can be used in neutral descriptions, but いい加減 often carries a negative judgment.
中途半端な努力では成功できない。
You can't succeed with half-hearted effort.
いい加減な仕事をすると信用を失う。
If you do half-hearted work, you'll lose trust.
Avoid directly translating 'half-hearted' as 半分の心 (はんぶんのこころ). It is not idiomatic and will sound unnatural.
The child started his homework half-heartedly.