| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [to-vb] [Wh det] happened to [noun] | 7 |
|
| 2 | [to-vb] what happened to [noun] | 7 |
|
| 3 | [to-vb] [pron] happened to [noun prp] | 7 |
|
| 4 | [to-vb] [pron] happened to [noun] | 7 |
|
| 5 | [to-vb] what happened to [noun] | 7 |
|
