| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] be seen [prep] [be] | 155 |
|
| 2 | [vb mod] be seen [prep] [be] | 155 |
|
| 3 | must be [verb] [prep] [be] | 71 |
|
| 4 | must be [vb pp] [prep] [be] | 70 |
|
| 5 | must be seen [prep] [be] | 32 |
|
| 6 | must be see [prep] [be] | 32 |
|
| 7 | must be seen [prep] [be] | 32 |
|
| 8 | must [be] seen [prep] [be] | 32 |
|
