| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | occur at [art] time [Wh adv] | 14 |
|
| 2 | occur at [art] time [Wh adv] | 14 |
|
| 3 | occur at [art] time when | 14 |
|
| 4 | occur at a time [Wh adv] | 13 |
|
| 5 | occur at a time [Wh adv] | 13 |
|
| 6 | occurred at [art] time [Wh adv] | 6 |
|
