出处:按学科分类—语言、文字 中国对外翻译出版公司《汉英成语词典》第290页(226字)
不能分辨豆或麦,比喻愚昧无知,例他不辨菽麦,偏偏好为人师,结果既害别人,也害了自己。
Though he knows nothing about practical matters,he loves to lecture others.No one benefits from his chitter-chatter,not even himself.