| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | what have happened to | 498 |
|
| 2 | what had [vb pp] to | 213 |
|
| 3 | what 's [vb pp] to | 183 |
|
| 4 | what has [vb pp] to | 162 |
|
| 5 | what have come to | 29 |
|
| 6 | what have got to | 5 |
|
