| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] have been done | 109 |
|
| 2 | could have been done | 43 |
|
| 3 | should have been done | 22 |
|
| 4 | would have been done | 13 |
|
| 5 | must have been done | 10 |
|
| 6 | will have been done | 8 |
|
| 7 | may have been done | 7 |
|
| 8 | might have been done | 7 |
|
