| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | what happened [prep] [noun prp] | 241 |
|
| 2 | [adv] what happened [prep] | 79 |
|
| 3 | [adv] happened [prep] [noun prp] | 27 |
|
| 4 | [adv] what [prep] [noun prp] | 20 |
|
