| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have [verb] [adj] | 519 |
|
| 2 | [modal v] have [verb] all | 205 |
|
| 3 | could [verb] [verb] all | 30 |
|
| 4 | could [vb infin] [verb] all | 30 |
|
| 5 | could have [verb] all | 22 |
|
