| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] have [be] | 21604 |
|
| 2 | [modal v] have [be] | 21604 |
|
| 3 | could [verb] [be] | 3102 |
|
| 4 | could have [be] | 2545 |
|
