| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must be [verb] | 12065 |
|
| 2 | [modal v] be return | 368 |
|
| 3 | must [be] return | 38 |
|
| 4 | must [be] return | 38 |
|
| 5 | must be return | 38 |
|
