| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must have be for | 14 |
|
| 2 | must have be for | 14 |
|
| 3 | must [vb infin] be for | 14 |
|
| 4 | must [verb] be for | 14 |
|
| 5 | must [verb] been for | 14 |
|
