| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh det] must be | 702 |
|
| 2 | [Wh det] must be | 702 |
|
| 3 | [Wh det] must [be] | 702 |
|
| 4 | [Wh det] must [be] | 702 |
|
| 5 | which must [be] | 563 |
|
| 6 | what must [be] | 139 |
|
