| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | why do [not/n't] [pron] [vb infin] back | 20 |
|
| 2 | why [vb base] n't [pron] [vb infin] back | 20 |
|
| 3 | why [vb base] [not/n't] [pers pn] [vb infin] back | 20 |
|
| 4 | why [vb base] [not/n't] you [vb infin] back | 17 |
|
| 5 | why [vb base] [not/n't] you [vb infin] back | 17 |
|
| 6 | why [vb base] [not/n't] [pron] go back | 12 |
|
| 7 | why [vb base] [not/n't] [pron] come back | 6 |
|
