| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have [vb pp] [adj] | 517 |
|
| 2 | [modal v] have [vb pp] [adj -er] | 87 |
|
| 3 | could have [vb pp] [adj -er] | 10 |
|
| 4 | could have [verb] [adj -er] | 10 |
|
| 5 | could [verb] [vb pp] [adj -er] | 10 |
|
| 6 | could [vb infin] [vb pp] [adj -er] | 10 |
|
