Cách sử dụng
The word 'rueful' means feeling or expressing sorrow or regret. It can be used when you feel sorry about something you did or when you regret not doing something. For example, if you forget to do an important task and feel bad about it, you can say "I have a rueful feeling about forgetting that task." It can also be used to describe someone's expression or tone of voice when they are expressing regret. So, it's a good word to use when you want to describe a feeling of sadness or regret about something.