If someone is dutiful, they do what is expected of them and behave in a loyal, obedient way. A dutiful son visits; a dutiful employee stays to the end of the meeting. It sounds a little formal, and sometimes a little cool.

If someone is dutiful如果一個人是dutiful的， they do what is expected of them就是會做別人期待他做的事， and behave in a loyal, obedient way表現得忠誠又聽話。 A dutiful son visits一個dutiful的兒子會回家探望； a dutiful employee stays to the end of the meeting一個dutiful的員工會留到會議結束。 It sounds a little formal這個詞聽起來有點正式， and sometimes a little cool有時候也帶點冷淡感。

Though actually, the word does not always mean the person is glad. It can mean they are doing the right thing because they should, not because their heart is running ahead of them — a dutiful smile, a dutiful letter of thanks. That shade is easy to miss if you only learn “good and loyal.” It is about duty as obligation (what you owe), not duty as a customs tax.

Though actually不過其實， the word does not always mean the person is glad這個詞不代表那個人心裡是開心的。 It can mean they are doing the right thing because they should它可能是說這個人做對的事，是因為他覺得應該這麼做， not because their heart is running ahead of them而不是因為心裡真的很想這麼做—— a dutiful smile, a dutiful letter of thanks像是一個dutiful的微笑、一封dutiful的感謝信。 That shade is easy to miss if you only learn "good and loyal."如果你只學到「善良又忠誠」，很容易漏掉這一層意思。 It is about duty as obligation (what you owe)這裡的duty指的是「義務」（你欠對方的）， not duty as a customs tax不是海關那個「關稅」的duty。

Common, but more at home in stories, family talk, and slightly careful English than in slang.

Common, but more at home in stories, family talk, and slightly careful English than in slang這個詞很常見，但更適合出現在故事、家庭對話，和比較講究的英文裡，而不是俚語中。