一心

いっしん

one mind, with rapt attention

JLPT N1

Character Breakdown

Meaning and Usage

"一心" (いっしん) literally means "one mind" or "wholeheartedly." It is used to express doing something with complete focus, dedication, or devotion. This word often appears in formal or literary contexts and conveys a strong sense of concentration or sincere intention.

Common Collocations

  • 一心に (いっしんに): adverbial form meaning "with all one's heart" or "single-mindedly." Used to describe actions done with full attention or devotion.
  • 一心不乱 (いっしんふらん): an idiomatic expression meaning "with undivided attention" or "without distraction."

Usage Notes

When using 一心, the speaker implies a deep commitment or intense focus on the subject. It is often paired with verbs like 願う (to wish), 取り組む (to tackle), or 勉強する (to study). Avoid using it in casual conversations as it sounds somewhat formal or literary.

Common Mistakes

Learners sometimes confuse 一心 with 一生 (いっしょう, lifetime) or 一緒 (いっしょ, together). Remember 一心 emphasizes mental focus or devotion, not time duration or companionship.

Example Sentences

かれはしけんにいっしんにとりくんでいる。

He is working on the exam with single-minded focus.

いっしんふらんにべんきょうすれば、かならずせいかがでる。

If you study with undivided attention, you will surely see results.

かのじょはこどものしあわせをいっしんにねがっている。

She wishes for her child's happiness with all her heart.