| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] could | 5341 |
|
| 2 | [not/n't] [vb mod] | 293 |
|
| 3 | [not/n't] [modal v] | 293 |
|
| 4 | [not/n't] could | 13 |
|
