| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] [pron] could [not/n't] [verb] | 588 |
|
| 2 | [vb past] [pron] could [not/n't] [vb infin] | 588 |
|
| 3 | [vb past] [pron] [modal v] [not/n't] have | 123 |
|
| 4 | [vb past] [pron] [vb mod] [not/n't] have | 123 |
|
| 5 | [verb] [pron] could [not/n't] have | 55 |
|
| 6 | [vb past] [pron] could [adv] have | 41 |
|
| 7 | [vb past] [pron] could [not/n't] have | 23 |
|
| 8 | [vb past] [pron] could [not/n't] have | 23 |
|
