| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] how [pron] could | 54 |
|
| 2 | [verb] how they could | 47 |
|
| 3 | [vb past] [adv] they could | 29 |
|
| 4 | [vb past] how they [modal v] | 16 |
|
