| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] which they must [vb infin] | 28 |
|
| 2 | [prep] [Wh det] they must have | 6 |
|
| 3 | of [Wh det] they must [vb infin] | 6 |
|
| 4 | in [Wh det] they must [vb infin] | 5 |
|
