| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [vb mod] have been [prep] that | 7 |
|
| 2 | it [modal v] have been [prep] that | 7 |
|
| 3 | it [modal v] have been [prep] that | 7 |
|
| 4 | it [modal v] have been [prep] that | 6 |
|
| 5 | it must have been [prep] that | 5 |
|
| 6 | it must have been [prep] that | 5 |
|
