| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have [been] [verb] [prep] | 4013 |
|
| 2 | must have [been] [verb] | 783 |
|
| 3 | must have [verb] [prep] | 701 |
|
| 4 | must have [been] [prep] | 289 |
|
