| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [vb pp] [prep] | 477791 |
|
| 2 | happen be [prep] | 29 |
|
| 3 | happen be [vb pp] | 15 |
|
| 4 | happen [vb pp] [prep] | 5 |
|
