| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [vb mod] [not/n't] have been [prep] | 15 |
|
| 2 | it [modal v] [not/n't] have been [prep] | 15 |
|
| 3 | it [modal v] [not/n't] have been [prep] | 15 |
|
| 4 | it [modal v] n't have been [prep] | 8 |
|
| 5 | it [modal v] not have been [prep] | 7 |
|
| 6 | it would [not/n't] have been [prep] | 5 |
|
| 7 | it could [not/n't] have been [prep] | 5 |
|
| 8 | it would [not/n't] have been [prep] | 5 |
|
| 9 | it could [not/n't] have been [prep] | 5 |
|
