| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [adv] be | 2734 |
|
| 2 | must [adv] be | 1920 |
|
| 3 | [modal v] either be | 280 |
|
| 4 | must either be | 36 |
|
| 5 | must either [be] | 36 |
|
