| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [vb mod] have been [prep] this | 10 |
|
| 2 | it [modal v] have been [prep] this | 10 |
|
| 3 | it must have been [prep] this | 5 |
|
| 4 | it must have been [prep] this | 5 |
|
| 5 | it have [adv] been [prep] this | 5 |
|
| 6 | it have been [verb] [prep] this | 12 |
|
| 7 | it have been [vb pp] [prep] this | 12 |
|
