از 10 عبارت زیر میتوانیم برای اطلاع رسانی در مورد کارشناس و ماهر بودن کسی در زبان انگلیسی استفاده کنیم :
He knows all about photgraphy.He's a camera expert.He's an expert on digital cameras.There's nothing he doesn't know about XHe knows photography inside out.You wouldn't believe what he knows about XHe's a walking encyclopaedia of XPhotography's his subject.He knows it from A - Z.He's an authority on digital cameras.