1、sad的基本意思是“悲哀的，忧愁的，难过的”，指由于不好的消息或结果等而使人在内心感到难过，也可指“糟糕的，不成样子的，不像话的”，指某人或某物以一种令人难以接受的形象出现而使人感到非常糟糕。

2、sad在句中可用作定语，也可用作表语。

用作表语时，其后可接介词短语、动词不定式或由that引导的从句。

sad英 [s?d] 美 [s?d] adj.悲哀的;难过的;让人无法接受的;该受责备(或批评)的;乏味的;状况不佳的比较级sadder最高级saddest牛津词典adj.【不规则形式】 sadder， saddest不快乐 unhappy1~ (to do sth) | ~ (that...)悲哀的；难过的；显得悲哀的unhappy or showing unhappinessWe are very sad to hear that you are leaving.听说你要走了，我们十分难过。

I was sad that she had to go.知道她得走了，我心里很难过。

She looked sad and tired.她看上去又伤心又疲惫。

I felt terribly sad about it.我对此深感遗憾。

He gave a slight， sad smile.他露出一丝苦笑。

The divorce left him sadder and wiser (= having learned from the unpleasant experience) .离婚使他痛苦，也使他长了心眼儿。

2~ (to do sth) | ~ (that…)令人悲哀的；让人难过的that makes you feel unhappya sad story悲伤的故事It was sad to see them go.看着他们离去，真让人难过。

It is sad that so many of his paintings have been lost.他的画作有很多已经失传了，真可惜。

We had some sad news yesterday.昨天我们听到一些不幸的消息。

He's a sad case─his wife died last year and he can't seem to manage without her.他是个不幸的人——去年死了老婆，而没她他好像就过不下去。

Sad to say (= unfortunately) the house has now been demolished.可惜那座房子现在已经拆了。

让人无法接受 unacceptable3让人无法接受的；该受责备（或批评）的unacceptable; deserving blame or criticism同义词： deplorablea sad state of affairs糟糕的局面It's a sad fact that many of those killed were children.让人难以接受的是遇难者中很多是孩子。

乏味 boring4(informal) 乏味的；过时的boring or not fashionableYou sad old man.你这糟老头子。

You'd have to be sad to wear a shirt like that.你穿着那样的衬衣显得老气。

状况不佳 in poor condition5状况不佳的in poor conditionThe salad consisted of a few leaves of sad-looking lettuce.色拉就是几片生菜的残叶。