| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [modal v] have had to | 9 |
|
| 2 | it [vb mod] [verb] had to | 9 |
|
| 3 | it [modal v] have had to | 9 |
|
| 4 | it [modal v] [vb infin] had to | 9 |
|
| 5 | it would [verb] had to | 7 |
|
| 6 | it would [verb] had to | 7 |
|
