| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have be [verb] [adj] | 12 |
|
| 2 | could have [been] [verb] [adj] | 12 |
|
| 3 | could have [be] [verb] [adj] | 12 |
|
| 4 | could have been [verb] [adj] | 12 |
|
| 5 | could have [be] [vb pp] [adj] | 10 |
|
