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kind and careful (instruction, explanation, etc.); considerate; helpful; thoughtful; detailed; scrupulous
先生の懇切丁寧な説明で理解が深まった。
The teacher's kind and thorough explanation deepened my understanding.
懇切な指導のおかげで技術が向上した。
Thanks to thoughtful instruction, my skills improved.
窓口の職員が懇切に対応してくれた。
The staff at the counter responded to me helpfully.