| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | how [verb] it happen [that] | 6 |
|
| 2 | how [verb] it happen [conj] | 6 |
|
| 3 | how [verb] it happen that | 6 |
|
| 4 | how [verb] it happen that | 6 |
|
