| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | has been [vb pp] [prep] a | 1756 |
|
| 2 | has been [vb pp] back [prep] | 48 |
|
| 3 | been [vb pp] back [prep] a | 15 |
|
| 4 | has [vb pp] back [prep] a | 5 |
|
