black sheep害群之馬。在工業發達前的年代，白羊的毛可以染成其他顏色，被視為有價值，黑羊的毛無法染色，因此被認為沒有經濟價值。後來就被用來表示「害群之馬"，不過，後來漸漸擺脫了負面意思，用以形容「特立獨行的人」。
看看老外聊天時怎麼用black sheep：
Allen: I have always been the black sheep in my family.
Mandy: What do you mean by that?
Allen: Ha-ha. I bother everyone with my surprises.
Mandy: I bet you are the youngest of your family.
Allen: You' re right! I am the baby of the family.
艾倫：我向來都是家裡的害群之馬。
曼迪：什麼意思？
艾倫：哈哈，我的驚喜總讓大家苦惱。
曼迪：你肯定是家裡最小的。
艾倫：你說對啦！我在我們家排行最小。
black sheep例句精選：
As the owner of the factory I'm like the head of a family,I can't allow any black sheep among my employees.
我在廠裡好比是一家之主，我不能容忍那種害群之馬。
There's a black sheep in every flock.
每一個團體中都難免有害群之馬。
I never heard anyone mention my uncle& I think he was a bit of a black sheep.
我從未聽到誰提到過我的叔叔，我想他有點像個敗家子。
My younger brother is the black sheep of the family.
我弟弟是我們家的敗家子。
John is considered a black sheep in the village and no one likes to make friends with him.
約翰被人看作村裡的害群之馬，沒有人願意和他交朋友。
拓展學習：
obey 服從
sheepish 影羞怯的
disturb 擾亂
offbeat 影非主流的；特異的
abide by 遵守
get off my back 別煩我
a party pooper 社交聚會時令人掃興的人或事