| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have [vb pp] a [adj] | 113 |
|
| 2 | could have [vb pp] [adj] [det] | 22 |
|
| 3 | have [vb pp] a [adj] [det] | 16 |
|
| 4 | could have [vb pp] a [det] | 7 |
|
