| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must have been [prep] [prep] | 12 |
|
| 2 | must have been [prep] [prep] | 12 |
|
| 3 | must [vb infin] been [prep] for | 8 |
|
| 4 | must have been [prep] for | 8 |
|
| 5 | [modal v] have been [prep] for | 8 |
|
| 6 | must have been [prep] for | 8 |
|
| 7 | must [verb] been [prep] for | 8 |
|
| 8 | must have been [prep] for | 8 |
|
| 9 | [vb mod] have been [prep] for | 8 |
|
| 10 | must have [be] [prep] for | 8 |
|
| 11 | must have [been] [prep] for | 8 |
|
| 12 | must have be [prep] for | 8 |
|
| 13 | must have been [prep] for | 8 |
|
