| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [vb pp] [prep] be [verb] | 554 |
|
| 2 | must be [vb pp] [prep] [verb] | 148 |
|
| 3 | must be [vb pp] [prep] be | 75 |
|
| 4 | must be [vb pp] be [verb] | 5 |
|
