| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have [vb pp] at [det] time | 7 |
|
| 2 | could have [vb pp] at [det] time | 7 |
|
| 3 | could have [vb pp] at any time | 7 |
|
| 4 | could have happened at [det] time | 5 |
|
