Earlier means happening before the present moment, or before some other point in time. If your piano lesson is at 4:00 but you arrive at 3:45, you've come earlier than expected. If your teacher mentions “as we discussed earlier,” she's referring to something that happened before right now, maybe at the beginning of class or even last week.

The word helps us talk about the order of events. When you read a mystery novel and the author writes “the clues mentioned earlier in the chapter,” you know to think back to what you've already read. When your mom says “I asked you earlier to clean your room,” she means she asked you before this conversation, and you probably should have done it by now.

Earlier is the comparative form of early, which describes something happening near the beginning of a period of time. Just as tall becomes taller and fast becomes faster, early becomes earlier when you're comparing two times. You might wake up early on a school day, but even earlier on the morning of a field trip because you're too excited to sleep.