战国时代，有一个叫公明仪的音乐家很会弹琴。很多人都喜欢听他弹琴，人们很敬重他。一天，公明仪在郊外游玩时，看到了一头牛。他想：大家都赞扬他的琴技，不如我给牛也弹一曲吧！给牛弹奏了一曲古雅的曲子，牛埋头吃草不理他。他又弹奏了一曲欢快的曲子，牛依然埋头吃草不理他。公明仪拿出自己的全部本领，结果牛还是不理会他。公明仪非常失望，开始怀疑自己的琴技。路人说：“不是你弹的琴不好，而是牛根本听不懂啊！”

       对牛弹琴的寓意：对牛弹琴比喻对蠢人谈论高深的道理，也用以讥笑说话的人不看对象。

       中英文对照:

      cast pearls before swine ——对牛弹琴

      During the Warring States Period, there was a musician named Gongming Yi, who played musicalinstruments very well.
      战国时代，有一个叫公明仪的音乐家，他很会弹琴。

      There were a great number of people fond of listening to him play, and respected him verymuch.
      很多人都喜欢听他弹琴，人们很敬重他。

      One day, Gongming Yi saw a cow when he was having fun in the countryside.
      一天，公明仪在郊外游玩时，看到了一头牛。

      He thought,"Everybody compliments my music. Why don't I play some music for this cow?"
      他想：大家都赞扬我的琴技，不如我给牛也弹一曲吧!

      He played a piece of elegant quaint music for the cow, but the cow just kept grazing the grasswith its head down.
      他给牛弹奏了一曲古雅的曲子，牛埋头吃草不理他。

      He played another piece of joyful music, but the cow still kept its head down to graze thegrass and totally ignored him.
      他又弹奏了一曲欢快的曲子，牛依然埋头吃草不理他。

      Gongming Yi was so disappointed and started to question his ability.
      公明仪拿出自己的全部本领， 结果牛还是不理他。公明仪非常失望，开始怀疑自己的琴技。

      A passerby said to him,"It's not because your ability is bad. It is because the cow can notunderstand music at all."
      路人说：“不是你弹的琴不好，而是牛根本听不懂啊!”

     【文化链接】
      “对牛弹琴”现在常用来比喻对愚人谈论高深的道理，白费口舌，英文中可以用“cast pearls beforeswine”来表达相应的意思，也就是“即使把珍珠丢到猪的面前，猪也不会珍惜在意”,同时也颇有“明珠暗投”的意味。来一起看一个例句：

      Don't waste your time and breath. It's not worth casting pearls before swine!
      别浪费你的时间和精力了，不值得和他对牛弹琴！