| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it must [vb infin] [be] | 782 |
|
| 2 | must [vb infin] [be] [prep] | 297 |
|
| 3 | it must [be] [prep] | 189 |
|
| 4 | it must [vb infin] [prep] | 159 |
|
| 5 | it [vb infin] [be] [prep] | 6 |
|
