| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun pl] must [vb infin] been [adj] | 53 |
|
| 2 | [noun pl] must have been [adj] | 53 |
|
| 3 | [noun pl] must have been [adj] | 53 |
|
| 4 | [noun pl] must [verb] been [adj] | 44 |
|
