| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [adv] have [vb pp] | 1824 |
|
| 2 | [adv] have [vb pp] [det] | 925 |
|
| 3 | could have [vb pp] [det] | 348 |
|
| 4 | could [adv] have [det] | 48 |
|
