| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have be [noun prp] | 39 |
|
| 2 | could have [be] [noun prp] | 39 |
|
| 3 | could have [been] [noun prp] | 38 |
|
| 4 | could have been [noun prp] | 38 |
|
