| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | back to [adv] [pron] | 147 |
|
| 2 | back to [Wh adv] [pron] | 142 |
|
| 3 | [adv] to how [pron] | 20 |
|
| 4 | back [prep] how [pron] | 10 |
|
| 5 | back [prep] how [pron] | 10 |
|
| 6 | back to how [pron] | 5 |
|
| 7 | back to how [pron] | 5 |
|
