| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could and [vb mod] [vb infin] been [verb] | 5 |
|
| 2 | could and [vb mod] have been [verb] | 5 |
|
| 3 | could and should [verb] been [verb] | 5 |
|
| 4 | could and [vb mod] have been [verb] | 5 |
|
| 5 | could and [vb mod] [verb] been [vb pp] | 5 |
|
