1. Telling him to study hard is like talking to the wall. He has no interest in school.2. Don't bother discussing the Bible with my brother; it would be like casting pearls before swine.
 talk to the wall cast pearls before swinetalk to the wall 形容對方根本不會聽你說的，類似的說法還有 It's like talking to a chimp. 而 cast pearls before swine 是正統的美國成語，但沒有很普遍，形容跟一個不懂欣賞某事的人敘述某事，就像給豬珍珠一樣。P.S. talk to the wind = 跟自己說話
1. 不用跟我弟弟聊莎士比亞, 那會像對牛彈琴一樣.2. 鼓勵他唸書就像對牛彈琴一樣.
I am much smarter than my husband, but it is important to protect his anhood.