1, metonymy is borrowing rather than replacing, metonymy is replacing rather than self-evident.
2. Metonymy focuses on similarity and metonymy focuses on relevance.
3. Metonymy can be simplified as simile, but metonymy can't. All three elements of metonymy reduction can appear, but metonymy can only be one.
In short, we should distinguish between metonymy and metonymy, and we should not be confused by the word "borrowing" except the concept connotation. The best way is to simplify them into three elements, and the right and wrong are clear at a glance.