| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh det] [verb] back [prep] the [num ord] | 14 |
|
| 2 | [Wh det] [verb] back [prep] the [num ord] | 14 |
|
| 3 | which [verb] back [prep] the [num ord] | 14 |
|
| 4 | [Wh det] [verb] back to the [num ord] | 13 |
|
| 5 | [Wh det] date back [prep] the [num ord] | 11 |
|
| 6 | [Wh det] [vb -s] back [prep] the [num ord] | 9 |
|
| 7 | [Wh det] dates back [prep] the [num ord] | 8 |
|
