| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] have been [adv] | 2776 |
|
| 2 | must have been [adv] | 562 |
|
| 3 | must [vb infin] been [adv] | 535 |
|
| 4 | must have been [adv] | 535 |
|
| 5 | must [verb] been [adv] | 535 |
|
| 6 | must have [be] [adv] | 522 |
|
| 7 | must have [been] [adv] | 522 |
|
| 8 | must have be [adv] | 522 |
|
