| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] happen to | 507 |
|
| 2 | [adv] happen to | 394 |
|
| 3 | [modal v] [adv] happen | 318 |
|
| 4 | [modal v] [adv] to | 84 |
|
