By vs Until vs Within Exercises
When learning English, certain prepositions can be tricky especially words like “by,” “until,” and “within.” Though they all relate to time, they are used in different contexts and with different meanings.
Meaning and Use of By
Definition:
“By” is used to show a deadline or the latest time something can be done.
✅ Use “By” to show:
- A task must be completed before or at a certain time
- A point in time when something happens
📌 Examples:
- You must finish the report by 5 PM.
- I will arrive by Monday.
- The train leaves by noon.
Meaning and Use of Until
Definition:
“Until” is used to indicate how long an action continues, from the past or present up to a certain point in time.
✅ Use “Until” to show:
- The duration of an activity
- Something will happen or continue up to a point in time
📌 Examples:
- She stayed until 9 PM.
- Wait here until I return.
- They worked until the sun went down.
Meaning and Use of Within
Definition:
“Within” is used to refer to something that happens inside a specific time limit.
✅ Use “Within” to show:
- Something occurs at any time before a deadline (inside a time frame)
📌 Examples:
- I’ll respond within 24 hours.
- The package arrived within two days.
- You must complete the task within a week.
By vs. Until vs. Within
| Preposition | Meaning | Focus On | Example |
|---|---|---|---|
| By | Not later than a time | Deadline | Finish the work by 6 PM. |
| Until | Continuing up to a time | Duration | Stay here until I come back. |
| Within | Inside a time limit | Time frame | Submit the form within 2 days. |
