| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | why they [vb mod] | 233 |
|
| 2 | why they [modal v] | 233 |
|
| 3 | [adv] they must | 209 |
|
| 4 | why [pron] must | 59 |
|
| 5 | why they must | 6 |
|
