emotion : 普通用词，词义中性。泛指因外界刺激而引起思想情感从细微变化到最强烈的发作。
- Like a lot of men, he finds it hard to express his emotions.
- My mother was overcome with emotion and burst into tears.
feeling : 普通用词，含义广。多指具体的或内心的感受，或表露出来的强烈情感。
- The feeling of loneliness suddenly overwhelmed him.
- There's a feeling of dissatisfaction with the government.
- I got the feeling that I was not welcome.
- Her performance seemed to me completely lacking in feeling.
passion : 指极强烈的感情、尤指愤怒、爱好等。也常指两性间的爱情。
- Football arouses a good deal of passion among its fans.
- At school, his early interest in music developed into an abiding passion.
- Politics and philosophy were his lifelong passions.
affection : 指对人的爱慕或深厚、温柔的感情。
- She felt no affection for the child.
- He had a deep affection for his aunt.
- The former president still holds a place in the nation's affections.
- Sula seems to have transferred her affections from Jon to his brother.
sentiment : 一般指由一种思想激起的感情，含较大的理智因素。
- There was no fatherly affection, no display of sentiment.
- There is no room for sentiment in business.