| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [det] [modal v] have been due | 14 |
|
| 2 | [det] [vb mod] have been due | 14 |
|
| 3 | this [modal v] have been due | 12 |
|
| 4 | [det] may have been due | 11 |
|
| 5 | [det] may have been due | 11 |
|
