By the Time
"possibly before but no later than when"
By the time is used by speakers to imagine or predict the relative timing of two activities or events in the past, present or future.
Compare these two expressions:
By the time versus When
| BY THE TIME | WHEN |
|---|---|
By the time introduces a clause in which the end-point of an activity is the time at which another activity is ongoing or completed. The clauses indicate relative-time events or activities. By means "before but no later than this time." See At vs. By |
When (at the time) introduces a clause in which an activity (of short duration) interrupts another activity that is ongoing. The clauses indicate same-time events or activities. |
By the time I get home,
the sun will be setting. (setting is ongoing)  |
When I get home,
the sun will be setting. (setting is ongoing)
|
By the time I arrive,
they will have eaten dinner. (eating is completed.) |
When I arrived,
I saw that they had already eaten dinner. (Reported as a past event.) |
Also see: When / While
Relative Timing of Future — ongoing v. completed
| FUTURE PROGRESSIVE | FUTURE PERFECT |
|---|---|
By the time introduces a clause in which the end-point of an activity is the time at which another activity will be ongoing. |
By the time introduces a clause in which the end-point of an activity is the time at which another activity will already be completed. |
By the time I leave work,
the sun will be setting. |
By the time I leave work,
the sun will have set. |
By the time I arrive,
they will be eating dinner. |
By the time I arrive,
they will have eaten dinner. |
Relative Timing of Present — ongoing v. completed
| PRESENT PROGRESSIVE | PRESENT PERFECT |
|---|---|
By the time introduces a clause in which the end-point of an activity is the time at which another activity will be ongoing. |
By the time introduces a clause in which the end-point of an activity is the time at which another activity will already be completed. |
By the time we leave, the sun is setting. (leave - present) |
By the time we leave, the sun has already set. (leave - present) |
By the time I arrive, they are eating dinner. |
By the time I arrive, they have eaten dinner. |
Relative Timing of Past — ongoing v. completed
| PAST PROGRESSIVE | PAST PERFECT |
|---|---|
By the time introduces a clause in which the end-point of an activity is the time at which another activity will be ongoing. |
By the time introduces a clause in which the end-point of an activity is the time at which another activity will already be completed. |
By the time we left work, the sun was setting. (left - past) |
By the time we left work, the sun had set.(left - past) |
By the time I arrived, they were eating dinner. |
By the time I arrived, they had eaten dinner. |
Common Mistake
| ERROR | FIX |
|---|---|
*By the time I will arrive, they will be eating dinner. |
By the time I arrive, they will be eating dinner. |
*Yellow highlighting indicates example of incorrect usage.
Practice
Imagining Future Events
- Select the correct verb form from the menu list.
- Then click the button to check your answer.