| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] have [been] [verb] [det] | 88 |
|
| 2 | must have [been] [verb] [adj] | 34 |
|
| 3 | must [verb] [been] [verb] [det] | 17 |
|
| 4 | must have [be] [verb] [det] | 17 |
|
