| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | who [verb] [prep] | 15675 |
|
| 2 | who [vb past] [prep] | 9041 |
|
| 3 | [pron] happened [prep] | 1950 |
|
| 4 | who happen [prep] | 114 |
|
