| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | 6 |
|
|
| 2 | [Wh pn] happened to [be] [adv] | 6 |
|
| 3 | [Wh pn] happened [prep] be [adv] | 6 |
|
| 4 | [Wh pn] happened [prep] [be] [adv] | 6 |
|
| 5 | who happened [prep] [be] [adv] | 6 |
|
