| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have [vb pp] [art] | 817 |
|
| 2 | have [vb pp] [art] [adj -er] | 190 |
|
| 3 | could have [art] [adj -er] | 15 |
|
| 4 | could have [vb pp] [adj -er] | 10 |
|
