| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh adv] it happen | 128 |
|
| 2 | [Wh adv] it happened | 99 |
|
| 3 | how it happen | 76 |
|
| 4 | why it happen | 31 |
|
| 5 | [Wh adv] it happens | 29 |
|
| 6 | where it happen | 10 |
|
| 7 | when it happen | 9 |
|
