| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pron] must have [been] [prep] | 180 |
|
| 2 | [pron] must have [been] [prep] | 180 |
|
| 3 | [pron] [modal v] have [been] for | 25 |
|
| 4 | [pron] must have [been] for | 8 |
|
| 5 | [pron] must have [be] for | 8 |
|
| 6 | [pron] must [verb] [been] for | 8 |
|
