Teaching of Grammars to Suck Eggs

I speak English, but I'm not. It's the dogs bollocks. Do you know what they're saying? You don't understand this person. What about Dwyomes? Hokkops are watching now, we are doing a miracle! Oh yes, no makes it easier on Photo Given! You can't teach an old dog new tricks. And I'll teach Granny to suck eggs. Teaching of grammars to suck eggs is an English saying refers to a person giving advice to another person in a subject in which the other person is already familiar. Don't worry, do. No, come back, Menny. As you see, these are... Granny.