| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [subord] it could [adv] have [verb] | 6 |
|
| 2 | [subord] it could have [been] [verb] | 12 |
|
| 3 | [subord] it could have been [verb] | 12 |
|
| 4 | [subord] it could have be [verb] | 12 |
|
| 5 | [subord] it could have [be] [verb] | 12 |
|
