donkey punchのようなどんな単語でも探してください。
 
1.
English expression meaning that a person is giving advice to someone else about a subject that they already know about (and probably more than the first person)
"I'm probably teaching granny to suck eggs, but............." (then explain in great detail what they already know/are expert in)
rawkarenによって 2013年10月09日(水)