| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [adv] have been | 176 |
|
| 2 | must [adv] have been | 153 |
|
| 3 | [modal v] always have been | 23 |
|
| 4 | must always [verb] been | 9 |
|
| 5 | must always have [been] | 9 |
|
| 6 | must always have been | 9 |
|
| 7 | must always have be | 9 |
|
| 8 | must always have [be] | 9 |
|
