| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which [adv] [verb] [prep] [be] | 165 |
|
| 2 | [pron] [adv] happen [prep] [be] | 107 |
|
| 3 | which [adv] happen [prep] [be] | 20 |
|
| 4 | [Wh det] [adv] happen [prep] [be] | 20 |
|
