Imperative means absolutely necessary or extremely urgent. When something is imperative, it must be done: there's no real option to skip it or delay it. If a teacher says it's imperative that you study for tomorrow's final exam, she means you really must do it because the consequences of not studying would be serious. When a doctor says it's imperative that a patient take their medicine, missing doses could have serious consequences.

The word carries a sense of command or requirement. You might hear someone say “it is imperative that we leave now” when a dangerous storm is approaching. The choice isn't really a choice anymore: the situation demands action.

In grammar, an imperative sentence gives a command or makes a request: “Close the door” or “Please pass the salt.” These sentences tell someone to do something, which connects to the word's broader meaning of necessity and requirement.

When something is imperative, it's almost as if the situation itself is commanding you to act. Understanding what's truly imperative versus what's merely preferable helps you make smart decisions about where to focus your energy and attention.