| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [det] [noun] | 6833 |
|
| 2 | back [prep] a [noun] | 1030 |
|
| 3 | back [prep] [det] [noun] | 618 |
|
| 4 | back a [det] [noun] | 61 |
|
| 5 | back [prep] a [det] | 33 |
|
