班门弄斧 的翻译有好多种
直译是 display one's slight skill before an expert. (在行家面前显示身手)
意译有(老外常这样表达):
1.teach a fish to swim
2.teach one's grandmother to suck eggs
请看下列例句:
He is always tell the director how to run the business; that's like teach his grandmother to suck eggs
他老是对总裁说该如何管理业务,就跟班门弄斧似的
Never offer to teach fish to swim.
不要教鱼游泳; 不要班门弄斧。