| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | what [verb] to | 2393 |
|
| 2 | what [vb past] to | 1302 |
|
| 3 | what happened [prep] | 1257 |
|
| 4 | [pron] happened to | 1195 |
|
| 5 | what happen to | 1120 |
|
