【成语来源】 

highly talented
才高八斗

Tsau Pi and Tsau Jr were sons of Tsau Tsau. Both were very gifted writers, and
Tsau Jr was especially quick-witted.
曹丕与曹植都是曹操的儿子,二者均有才华,特别是曹植更具文采。

After Tsau Tsau's death, Tsau Pi took over the throne of the kingdom of wei. Jealous
of Tsau Jr's literary ability, and afraid that he might cause problems, Tsau Pi was always looking for a way to kill his brother.
在曹操死后,曹丕继任大统,但他嫉妒曹植的才华,同时也惧怕曹植回谋反,所以一直在伺机杀害曹植。

One day, Tsau Pi called Tsau Jr into see him.He ordered his brother to make up a poem within the time it took to walk seven steps, adding that if he could not, his life would be in danger.
有一天,曹丕要求接见曹植,他要求曹植在他七步之内作诗一首,如果做不到,就会有生命危险。

Greatly saddened, Tsau Jr began to walk and to think. Before he had taken the seven steps, he had already finished his poem, the meaning of which was: "Brothers are of the same family, so why should the oppress each other?"
悲愤之下,曹植急中生智,作出七步诗,是的意思就是“本来就是亲兄弟,为什么要这样步步紧逼,伤及感情?”

Tsau Jr was very intelligent and loved to study. He wrote many outstanding articles which showed his artistic talent and earned him the admiration of many people. One scholar said of him: "Heaven gave the world ten decalitres of talent, and Tsau Jr alone has eight of them."
曹植文采俱佳,热爱学习,他曾做过不少才华横溢的文赋,均令世人感叹不已。曾有一位学者说道:“如若天下文采共有十斗,曹植一人独占八斗。”

Today, to say that a person "has eight decalitres of talent" is to say that he has a great aptitude for writing.
今天,如果我们说一个人“才高八斗”,就是指他“才华横溢,很有文采”。

【文化链接】

英文中“才高八斗”并没有特别固定的说法,“highly talented”就可以表达相应的意思,当然“highly gifted”或者是“extremely talented”都是可以的。