| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [adv] [vb infin] | 32770 |
|
| 2 | could [not/n't] [vb infin] | 21338 |
|
| 3 | [not/n't] [adv] [vb infin] | 18399 |
|
| 4 | could [not/n't] [adv] | 1875 |
|
