| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] could [verb] | 668 |
|
| 2 | [Wh adv] [vb mod] [verb] | 78 |
|
| 3 | [Wh adv] [modal v] [verb] | 78 |
|
| 4 | [Wh adv] could [verb] | 9 |
|
