| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must have [verb] [pron] [vb past] | 40 |
|
| 2 | [modal v] have [verb] i [vb past] | 21 |
|
| 3 | must have [verb] i [verb] | 12 |
|
| 4 | must [verb] [verb] i [vb past] | 5 |
|
