| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pron] could [adv] have | 1770 |
|
| 2 | [vb past] [pron] could [adv] | 963 |
|
| 3 | [vb past] [pron] [adv] have | 251 |
|
| 4 | [vb past] [pron] could have | 163 |
|
| 5 | [vb past] could [adv] have | 8 |
|
