| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [subord] [pron] could [adv] have | 139 |
|
| 2 | [vb past] [subord] [pron] could [adv] | 55 |
|
| 3 | [vb past] [pron] could [adv] have | 41 |
|
| 4 | [vb past] [subord] [pron] could have | 19 |
|
| 5 | [vb past] [subord] [pron] [adv] have | 13 |
|
