The words "early" and "prompt" both relate to time, but they have different meanings. "Early" means before the expected or usual time. "Prompt" means done quickly and without delay; it suggests efficiency and readiness. While something early might be considered good or bad depending on the context, something prompt is usually positive.
Here are some example sentences to illustrate the difference:
Early:
Prompt:
Notice that "early" focuses on being before a certain time, while "prompt" emphasizes the speed and readiness of an action. You wouldn't say "He was early in replying" because being early only describes timing; you'd use "He was quick/fast in replying" or "He promptly replied."
Let's look at another example:
Imagine a deadline. If you submit your assignment early, it means you submitted it before the deadline. If you submit it promptly, it means you submitted it as soon as possible. You could submit it both early and promptly, or just early, or just promptly. But you can't submit it promptly but not on time.
Happy learning!