adverb
comfortably; pleasantly; cheerfully
Describes a comfortable, pleasant state or manner, often used with verbs like 過ごす, 眠る, or 笑う.
新しいソファで快く過ごせた。
I was able to spend time comfortably on the new sofa.
彼女は快く笑ってくれた。
She gave a cheerful laugh for me.
adverb
Expresses doing something with a willing, positive attitude, often in response to a request or invitation.
彼は快く手伝ってくれた。
He willingly helped me.
快く引き受けてください。
Please accept it gladly.