| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must have been [prep] | 294 |
|
| 2 | [modal v] have been worth | 28 |
|
| 3 | must have [be] worth | 6 |
|
| 4 | must have [been] worth | 6 |
|
| 5 | must have be worth | 6 |
|
| 6 | must [verb] been worth | 6 |
|
