| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it had [verb] | 4638 |
|
| 2 | it had [to-vb] | 296 |
|
| 3 | it had happen | 171 |
|
| 4 | it [verb] to happen | 33 |
|
| 5 | [pron] had to happen | 22 |
|
| 6 | it [vb past] to happen | 21 |
|
| 7 | it have to happen | 20 |
|
