| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | how [pron] could have [verb] | 57 |
|
| 2 | how [pers pn] could have [verb] | 52 |
|
| 3 | how it [vb mod] have [verb] | 32 |
|
| 4 | how it [modal v] have [verb] | 32 |
|
| 5 | [adv] it could have [verb] | 22 |
|
| 6 | how it could [verb] [verb] | 15 |
|
| 7 | how it could have [verb] | 15 |
|
| 8 | how it could have [verb] | 15 |
|
| 9 | how it could have [verb] | 15 |
|
| 10 | [Wh adv] it could have [verb] | 15 |
|
