Past refers to the time before now: everything that has already happened. Yesterday is in the past. Last week is in the past. The dinosaurs lived in the past. Your baby pictures are from the past.

When we study history, we're learning about the past: the people who lived before us, the events that shaped the world, and the inventions that changed how people live. Understanding the past helps us make sense of the present. If you want to know why your town has certain buildings or traditions, you look to the past for answers.

The word past also means beyond or by something. If you walk past the library, you go by it without stopping. If someone waves as they drive past your house, they're moving beyond where you're standing. A runner might sprint past other competitors to win a race.

Past can describe something that's finished or over. A past president is someone who used to hold that office but doesn't anymore. Your past mistakes are errors you made before, which you hopefully learned from. When something is in the past, it's done and behind you. People sometimes say “that's all in the past now” when they want to move forward and not dwell on what already happened.