| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [vb infin] [adv] | 3625 |
|
| 2 | could [vb infin] have | 298 |
|
| 3 | could have [adv] | 227 |
|
| 4 | [vb infin] have [adv] | 164 |
|
