| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | may [vb infin] been [vb pp] on | 24 |
|
| 2 | may have been [vb pp] on | 24 |
|
| 3 | may have been [vb pp] on | 24 |
|
| 4 | may [verb] been based on | 5 |
|
