| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] have been [verb] an | 21 |
|
| 2 | [vb mod] have been [v-ing] an | 9 |
|
| 3 | [vb mod] have been [vb pp] an | 9 |
|
| 4 | should have been [verb] an | 5 |
|
| 5 | would have been [verb] an | 5 |
|
