| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have [been] [vb pp] [art] | 8 |
|
| 2 | could have been [vb pp] [art] | 8 |
|
| 3 | could have [been] [vb pp] a | 8 |
|
| 4 | could have [been] [vb pp] a | 8 |
|
