Whenever means at any time that something happens, or every time that something happens. If your teacher says “raise your hand whenever you have a question,” she means you can do it at any moment a question pops into your head. If your dad tells you “we can play catch whenever you finish your homework,” he means the moment you're done, you can go play.

The word connects two things in time without pinning down exactly when. “Come over whenever you want” means you're welcome at any point, not just at 3:00 or 5:00. “Whenever it rains, the basement floods” means every single time rain falls, the same problem happens.

Notice how whenever differs from when. “When are we leaving?” asks for a specific time. “We'll leave whenever everyone's ready” keeps it flexible and open. Whenever is particularly useful when you don't know exactly when something will happen, or when you want to give someone freedom to choose the timing.