熱心 describes earnest, diligent enthusiasm (e.g. for study or work), while 熱烈 conveys a more burning, emotional passion (e.g. love or fervent support).
熱心 is the common, everyday word for being eager or enthusiastic, while 切 is a more formal, literary term used mainly in fixed phrases like 切に願う.
熱心 describes an earnest, enthusiastic attitude, while しきりに can describe both that eagerness and the repeated actions expressing it.
熱心 describes eagerness or enthusiasm toward something, while 一心 emphasizes single-minded focus rather than the feeling of enthusiasm itself.
熱心 is a noun/na-adjective describing steady dedication or zeal, whereas 意気込む is a verb capturing the moment of psyching oneself up for a task.
熱心 describes eager enthusiasm toward something, whereas 一心に highlights total mental concentration without distraction.
熱心 emphasizes enthusiasm and eagerness for a particular activity, whereas 勤勉 emphasizes consistent, disciplined effort over time.
熱心 describes a general eager or diligent attitude toward something, while 熱中 describes being actively and deeply absorbed in a specific pursuit right now.
熱心 means keen and enthusiastic in a calm, positive sense, while 躍起 implies a more agitated, single-minded intensity that can look desperate.
熱心 describes enthusiastic, eager effort, while 真摯 describes a sincere, serious-minded attitude that need not involve visible enthusiasm.
熱心 conveys diligent enthusiasm or zeal put into an effort, while 乗り気 is simply being inclined to accept or try something.
