| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [not/n't] [vb infin] they [adv] | 26 |
|
| 2 | could [not/n't] [verb] they [adv] | 26 |
|
| 3 | could [not/n't] they [adv] [vb infin] | 6 |
|
| 4 | could [not/n't] they [adv] [verb] | 6 |
|
