| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] have been [vb pp] at a | 8 |
|
| 2 | [vb mod] have been [vb pp] at a | 8 |
|
| 3 | have been [vb pp] at a [noun sg] | 5 |
|
| 4 | have been [vb pp] at a [noun] | 5 |
|
