| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | why [vb past] n't they [vb infin] | 43 |
|
| 2 | why did [not/n't] they [vb infin] | 43 |
|
| 3 | why [vb past] [not/n't] they do | 5 |
|
| 4 | why [vb past] [not/n't] they get | 5 |
|
