By vs At: Clarifying Time Expressions in English

Discover how to use "by" and "at" correctly in time expressions with this helpful video.

"At" indicates a specific time when something will happen. Use "at" when you want to specify the exact time something will occur, neither before nor after. For example, "I will finish it at 6 o'clock" means you will complete the task precisely at that time.

"By" indicates a deadline or the latest time something will happen. Use "by" when you want to indicate that something will be completed any time before the specified time. For example, "I will finish it by 6 o'clock" means you will complete the task any time between now and 6 o'clock, but no later than 6 o'clock.

Key takeaways:

• Use at for exact times.
• Use by for deadlines or the latest possible times.