| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must have [been] [vb pp] [prep] | 237 |
|
| 2 | [det] have [been] [vb pp] [prep] | 17 |
|
| 3 | [det] must have [vb pp] [prep] | 15 |
|
| 4 | [det] must have [been] [vb pp] | 13 |
|
| 5 | [det] must have [been] [prep] | 11 |
|
