| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it must [vb infin] be [adv] | 120 |
|
| 2 | it must [vb infin] be [prep] | 83 |
|
| 3 | must [vb infin] be [adv] [prep] | 23 |
|
| 4 | it must [vb infin] [adv] [prep] | 19 |
|
| 5 | it must be [adv] [prep] | 8 |
|
