Mastering prepositions in English as an Additional Language (EAL) can be challenging, especially when it comes to similar words like “by or until.” Both are used to talk about time, but they serve different functions and are not interchangeable.

By or Until: When to Use Each?

“By” sets a deadline (e.g., finish by Friday). “Until” marks the duration up to a point (e.g., work until Friday). “By” emphasizes the endpoint; “until” emphasizes the time span leading to the endpoint. Both indicate time limits but in different contexts.

Understanding “By”

“By” is used to indicate a deadline or the latest time something can happen. It emphasizes the end point, meaning an action or event should happen on or before a specific time. Think of it as a target that should be met before or at a particular moment.

Examples of “By”:

1. Please submit your assignment by Friday.
2. The package should arrive by 3 PM tomorrow.
3. She promised to call me by the end of the day.
4. We need to finish this project by the end of the month.
5. Can you be home by 6 PM?
6. The store closes by 8 PM on weekdays.
7. Make sure to send your application by the 15th.
8. The report must be ready by next Monday.
9. They hope to complete the construction by June.
10. I have to pay my bills by the 5th of each month.

Understanding “Until”

“Until” is used to refer to the duration or continuation of an action up to a specific time. It focuses on the period leading up to the endpoint. Think of it as a time span from now to a particular moment in the future.

Examples of “Until”:

1. You can stay here until Sunday.
2. The library is open until 9 PM.
3. She worked on her project until midnight.
4. We will wait until the rain stops.
5. The sale lasts until the end of the week.
6. He will be away until next month.
7. They won’t start the meeting until everyone arrives.
8. The show runs until the 30th of April.
9. I am on vacation until the 15th.
10. The restaurant serves breakfast until 11 AM.

Key Differences and Tips

• Use “by” to indicate a deadline or a specific point in time something should happen.
  • Tip: Think of “by” as a target date or time.
• Use “until” to talk about an action or state that continues up to a particular time.
  • Tip: Imagine “until” as highlighting the period leading up to an endpoint.

Practice:

To help solidify your understanding, try creating your own sentences using “by” and “until.” Think about the context and whether you are talking about a deadline or a duration.

Recap:

• By: Deadline (Submit by Monday)
• Until: Duration (Open until 6 PM)

With these guidelines and examples, you should feel more confident in using “by” and “until” correctly in your English writing and speaking. Happy learning!