| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [vb infin] been [prep] | 294 |
|
| 2 | must [vb infin] been some | 43 |
|
| 3 | must [vb infin] [prep] some | 41 |
|
| 4 | [vb infin] been [prep] some | 23 |
|
