| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | why did they [vb infin] | 109 |
|
| 2 | why [vb past] they [vb infin] | 109 |
|
| 3 | why [vb past] they do | 13 |
|
| 4 | why [vb past] they have | 7 |
|
| 5 | why [vb past] they choose | 5 |
|
| 6 | why [vb past] they put | 5 |
|
