I can see they are difficult to learn. Most people who use them (and we do, every day, without realizing it) have no idea that there even are grammatical terms for what they just said.
Common ones are referring to a place/office to represent the person. "The White House said..." "The reaction from Downing Street was swift and severe."
But in reading about this just now, I found examples that I never even notice as being a figure of speech, like "a lot of new faces." Well, obviously, the rest of the person showed up too. How gross would it be if just the faces showed up! But that's another example of "one part representing the whole."
Wholegrain seems to be struggling with this too. You two should join forces.