| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must be [vb pp] [subord] it [verb] | 7 |
|
| 2 | must [be] [vb pp] [subord] it [vb -s] | 7 |
|
| 3 | must be [vb pp] [subord] it [verb] | 7 |
|
| 4 | must [be] [vb pp] [subord] it [verb] | 7 |
|
