| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have [verb] | 5175 |
|
| 2 | [modal v] have see | 836 |
|
| 3 | could [verb] see | 89 |
|
| 4 | could [vb infin] see | 89 |
|
| 5 | could have see | 54 |
|
