| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] what they must | 7 |
|
| 2 | what they must [vb infin] | 19 |
|
| 3 | what they must [verb] | 19 |
|
| 4 | what they must do | 11 |
|
| 5 | what they must do | 11 |
|
