Cách sử dụng
The expression "nail down" means to make something very clear and specific. It's often used in situations where you need to finalize plans or make a decision. For example, you might say "let's nail down the details of our vacation" to mean that you want to make sure everything is planned out and confirmed. It can also be used to mean achieving a certain level of accuracy or precision in a task or goal. For example, "I need to nail down the presentation to make sure it's perfect."