有个楚国贵族，在祭祀过祖宗后，把一壶祭酒赏给门客们喝。门客们拿着这壶酒，不知如何处理。他们觉得，这么多人喝一壶酒，肯定不够，还不如给一个人 喝，还可以喝得痛快些。可是到底给谁好呢？于是，门客们商量了一个好主意，就是每个人各自在地上画一条蛇，谁先画好了这壶酒就归谁喝。大家都同意这个办 法。
门客们一人拿一根小棍，开始在地上画蛇。有一个人画得很快，不一会儿，他就把蛇画好了，于是他把酒壶拿了过来。他正要喝酒时，看见其他人还没把蛇画完，他便十分得意地又拿起小棍，边自言自语地说：“看我再来给蛇添上几只脚，他们也未必画完。”边说边给画好的蛇画脚。
正在他一边画着脚，一边说话的时候，另外一个人已经画好了。那个人马上把酒壶从他手里夺过去，在他还没来得及抗议， 就听见其他人都对着他的画大笑起来，“看看他画的蛇， 还长着脚呢！”
“蛇是没有脚的，你为什么要给他添上脚呢？所以第一个画好蛇的人不是你，而是我了！”
那个人说罢就仰起头来，咕咚咕咚把酒喝下去了。
解释 Explanation to the idiom:
以后人们根据这个故事引申出”画蛇添足”这句成语，比喻有的人自作聪明，常做多余的事，反而弄巧成拙，把事情办糟了。
生词 New words:
祭祀 jìsì: fete；sacrifice
祖宗 zǔzōng: ancestor; forefather; forebear
痛快 tongkuài: here the meaning is .(enjoying something) without restraint;
好主意 hǎo zhúyì: good idea
自言自语 zìyán zìyǔ: to talk (or speak) to oneself; to say sth. to oneself; to think aloud; to soliloquize
词语应用 Application of the new words
(1) 他这个人个性有点奇怪，总喜欢边走路，边自言自语。
(2) 在中国古代，祭祀祖宗是很重要的一种仪式。
(3) 你这篇文章写到这里已经很明白了， 再加上这个结尾就画蛇添足了。
翻译 Translation:
Draw a Snake by Adding Feet to It
This story dates back as early as the State of Chu (770 – 476 B.C.). One day in an ancestral temple after the Spring Sacrifice ceremony, an official offered his men a jar of rice wine. Since there was only enough for one person, they all agreed that each of them should draw a snake; and the quickest one could drink the wine.
They all began to draw snakes. In just a few minutes, one man finished, but seeing the others still busy with their brushes, he couldn’t help adding some strokes to improve his drawing.
When he finally finished his improvements, he found, to his great surprise, that someone else had already finished drawing and was ready to get the drink.
Before he could protest, he heard the others burst into laughter at his drawing, “Look at his snake! A snake with feet!” So the first one lost his chance, and the drink went to the second competitor.
Hence the expression ” 画蛇添足 “ (Draw a snake by adding feet to it.)
Moral: Do the superfluous thing causing a negative effect just like Carrying coals to New Castle .
(Source:english.cri.cn)