| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] [prep] [been] | 422 |
|
| 2 | [modal v] [prep] [been] | 422 |
|
| 3 | must [prep] [be] | 149 |
|
| 4 | must [prep] [been] | 147 |
|
