worry、brood、care与fret这些动词均有“烦恼、担忧”之意。
worry : 普通用词，着重使人焦虑、烦恼或深深不安。
- Try not to worry - there's nothing you can do to change the situation.
别发愁了——你没法改变这种局面。 - Don't worry, she'll be all right.
别担心，她会没事的。
brood 语气比 worry 强，多指沉思、沮丧或忧郁。
- I wish she wouldn't sit brooding in her room all day.
我希望她不要整天呆在房间里忧心忡忡的。
care : 多指极强烈的关心和忧虑。常带纯客观的意味。
- She's never cared very much about her appearance.
她对自己的外表从不很在意。 - I really don't care whether we go out or not.
我们出不出去我真的不在意。
fret : 通常指因悲哀、焦虑或忧愁等所持续困扰的心理状态。
- Don't fret - I'm sure he's OK.
别发愁——他肯定没事。 - She spent the day fretting about/over what she'd said to Nicky.
她为对尼基说的话而担心了一整天。
延伸阅读：小词详解 | fret
