| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [v-ing] back to | 1857 |
|
| 2 | [vb pp] back to | 1459 |
|
| 3 | [v-ing] [vb pp] to | 313 |
|
| 4 | [v-ing] [vb pp] back | 33 |
|
