| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | what has happened to [adj] | 16 |
|
| 2 | what has happened [prep] [adj] | 10 |
|
| 3 | what [verb] happened to [adj] | 10 |
|
| 4 | what has happened [prep] [adj] | 10 |
|
| 5 | what have happened to [adj] | 10 |
|
| 6 | what [vb -s] happened to [adj] | 8 |
|
| 7 | [pron] has happened to [adj] | 6 |
|
| 8 | what has happened to [adj] | 6 |
|
| 9 | what has [verb] to [adj] | 6 |
|
| 10 | what has [vb pp] to [adj] | 6 |
|
| 11 | what has happen to [adj] | 6 |
|
