| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it have been [vb pp] by a | 60 |
|
| 2 | it had been [verb] by a | 28 |
|
| 3 | it has been [verb] by a | 21 |
|
| 4 | it 's been [verb] by a | 10 |
|
