| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | why [verb] [adv] [pers pn] [vb infin] back | 27 |
|
| 2 | why [verb] not [pers pn] [vb infin] back | 27 |
|
| 3 | why [verb] n't [pers pn] [vb infin] back | 27 |
|
| 4 | why [verb] [not/n't] [pers pn] [vb infin] back | 27 |
|
| 5 | why [verb] [pers pn] [vb infin] back [prep] | 5 |
|
| 6 | why [verb] [pers pn] [vb infin] back [prep] | 5 |
|
