| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | why do [pron] [vb infin] back | 18 |
|
| 2 | why do [pron] [verb] back | 18 |
|
| 3 | why did [pron] [verb] back | 18 |
|
| 4 | why do [pers pn] [verb] back | 18 |
|
| 5 | why do [pron] come back | 14 |
|
| 6 | why do [pron] come back | 14 |
|
| 7 | why do you [verb] back | 11 |
|
| 8 | why do you [verb] back | 10 |
|
