| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | what have happened [prep] | 780 |
|
| 2 | what have happen to | 498 |
|
| 3 | what had happen [prep] | 339 |
|
| 4 | what has happen [prep] | 225 |
|
| 5 | what 's happen [prep] | 215 |
|
| 6 | what have happen in | 132 |
|
| 7 | what have happen at | 30 |
|
| 8 | what have happen with | 28 |
|
| 9 | what have happen on | 18 |
|
| 10 | what have happen between | 14 |
|
| 11 | what have happen since | 13 |
|
| 12 | what have happen during | 9 |
|
| 13 | what have happen after | 7 |
|
| 14 | what have happen over | 7 |
|
| 15 | what have happen before | 6 |
|
