| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb infin] [Wh det] happened to | 63 |
|
| 2 | [vb infin] what happened to | 62 |
|
| 3 | know [Wh det] happened to | 37 |
|
| 4 | care [Wh det] happened to | 8 |
|
