| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [verb] been [det] [noun] [adv] | 7 |
|
| 2 | must have been [det] [noun] [adv] | 7 |
|
| 3 | must [vb infin] been [det] [noun] [adv] | 7 |
|
| 4 | must have been [det] [noun] [adv] | 6 |
|
| 5 | must [verb] been [det] [noun] [adv] | 6 |
|
| 6 | must [verb] been [det] [noun pl] [adv] | 5 |
|
