| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [verb] been a [noun] | 181 |
|
| 2 | [noun pl] [verb] been a [noun] | 116 |
|
| 3 | [noun pl] must [verb] a [noun] | 88 |
|
| 4 | [noun pl] must [verb] been a | 8 |
|
