Cách sử dụng
The expression "be not to know" means that you are not expected to know something or it is not something you should worry about. It is commonly used to indicate that a particular piece of information or detail is not important or relevant to a situation. For example, if a friend asks you about a fact that you are not sure of, you could say "I'm sorry, but that's not something I know. It's not to be known."