unhappy 不開心的
I didn't realize but he was deeply unhappy at that time.
我沒有察覺到他那時非常不開心。
I can see that he's unhappy, but I don't know why.
我能看出來他不開心，但是我不知道為什么。

miserable 非常難過的
We were cold, wet and thoroughly miserable.
我們又冷又濕，難受極了。
Don't look so miserable!
別一副悶悶不樂的樣子！

upset 難過的，沮喪的；使人沮喪；肚子不舒服
This decision is likely to upset a lot of people.
這項決定很可能會讓許多人不快。
There's no point getting upset about it.
犯不著為此事難過。
I had an upset stomach after eating all those cookies.
吃完所有的餅干之后，我的肚子不舒服了。

depressed 沮喪的，憂郁的
She felt very depressed about the future.
她感到前途無望。
The rainy weather made her feel lonely and depressed.
雨天讓她覺得孤獨(dú)難過。

down 難過的
I feel a bit down today.
我今天有點(diǎn)悶悶不樂。

blue 憂郁的
He'd been feeling blue all week.
他整個星期都郁郁不樂。

gloomy 沉悶的，不悅的
It was a wet and gloomy day.
那一日陰天下雨沉悶無聊。
We sat in gloomy silence.
我們郁郁不樂默不作聲地坐著。

frustrated 令人懊惱的
It's very easy to get frustrated in this job.
這個工作很容易令人懊惱。
They felt frustrated at the lack of progress.
沒有進(jìn)展，他們感到懊喪。

a long face 拉長臉，不開心
A long face won't solve anything.
拉長個臉解決不了任何事情。
Why the long face?
干嘛拉長個臉？

down in the dumps 難過的
She's still pretty down in the dumps.
她仍然十分沮喪。
Reshma has been so down in the dumps since her boyfriend left her.
自從她的男朋友拋下她以后，瑞斯曼就一直情緒低落。