| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it have happened to | 33 |
|
| 2 | it [verb] happened to | 33 |
|
| 3 | it [vb -s] happened to | 17 |
|
| 4 | it [vb past] happened to | 16 |
|
| 5 | it had happened to | 15 |
|
| 6 | it 's happened to | 13 |
|
