| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | who have [vb pp] back to | 15 |
|
| 2 | [Wh pn] have [vb pp] back to | 15 |
|
| 3 | [Wh pn] had [vb pp] back to | 7 |
|
| 4 | [Wh pn] have come back to | 5 |
|
