| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it must have been a [noun] | 51 |
|
| 2 | it must [vb infin] been a [noun] | 51 |
|
| 3 | it must [verb] been a [noun sg] | 50 |
|
| 4 | it must have been a [noun] | 50 |
|
| 5 | it must [verb] been a shock | 6 |
|
| 6 | it must [verb] been a shock | 6 |
|
