| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must have [be] something [prep] [det] | 5 |
|
| 2 | must have be something [prep] [det] | 5 |
|
| 3 | must have [been] something [prep] [det] | 5 |
|
| 4 | must have been something [prep] [det] | 5 |
|
