| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [verb] at a time when | 8 |
|
| 2 | it was at a time when | 7 |
|
| 3 | it be at a time when | 7 |
|
| 4 | it [be] at a time when | 7 |
|
| 5 | it [was/were] at a time when | 7 |
|
| 6 | it come at a time when | 5 |
|
