| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [det] could have been [verb] | 50 |
|
| 2 | [det] could have been [verb] | 50 |
|
| 3 | [det] could have been [vb pp] | 49 |
|
| 4 | this could have been [verb] | 18 |
|
| 5 | that could have been [verb] | 14 |
|
| 6 | [det] could have been done | 13 |
|
| 7 | [det] could have been do | 13 |
|
| 8 | more could have been [verb] | 10 |
|
| 9 | [det] could have been achieve | 8 |
|
| 10 | [det] could have been achieved | 8 |
|
