| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] have been in | 465 |
|
| 2 | must have been [prep] | 294 |
|
| 3 | must have [be] in | 89 |
|
| 4 | must [verb] been in | 89 |
|
| 5 | must have [been] in | 89 |
|
| 6 | must have be in | 89 |
|
