| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [not/n't] [vb infin] | 21338 |
|
| 2 | [Wh pn] could [vb infin] | 1264 |
|
| 3 | [Wh pn] could [not/n't] | 447 |
|
