| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must be | 23970 |
|
| 2 | must be | 23956 |
|
| 3 | must [be] | 23956 |
|
| 4 | must [been] | 5 |
|
| 5 | must [is] | 5 |
|
| 6 | must been | 5 |
|
| 7 | must is | 5 |
|
