| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] not [verb] | 44079 |
|
| 2 | could [adv] [verb] | 32838 |
|
| 3 | could [not/n't] [verb] | 21358 |
|
| 4 | could not [verb] | 21336 |
|
