| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh adv] could [pers pn] [verb] | 889 |
|
| 2 | could [not/n't] [pers pn] [verb] | 335 |
|
| 3 | [Wh adv] could [not/n't] [pers pn] | 137 |
|
