| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] it [adv] | 9399 |
|
| 2 | [vb past] [adv] happen | 476 |
|
| 3 | it [adv] happen | 405 |
|
| 4 | [vb past] it happen | 124 |
|
