| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have [vb pp] [adj] | 534 |
|
| 2 | [modal v] have [vb pp] all | 157 |
|
| 3 | could have [verb] all | 22 |
|
| 4 | could [verb] [vb pp] all | 22 |
|
