| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [not/n't] have [verb] [pron] | 219 |
|
| 2 | [modal v] [not/n't] have [verb] i | 80 |
|
| 3 | could [not/n't] [verb] [verb] i | 27 |
|
| 4 | could [adv] have [verb] i | 23 |
|
