| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [adv] [verb] [prep] | 417 |
|
| 2 | must [verb] been [prep] | 294 |
|
| 3 | [adv] [verb] been [prep] | 285 |
|
| 4 | must [adv] [verb] been | 153 |
|
