| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [be] [vb pp] [prep] an [adj] | 66 |
|
| 2 | must [be] [vb pp] [prep] an [adj] | 66 |
|
| 3 | [modal v] [be] [vb pp] at an [adj] | 48 |
|
| 4 | must [be] [vb pp] at [art] [adj] | 25 |
|
| 5 | must [be] [vb pp] at [art] [adj] | 25 |
|
| 6 | must [be] [vb pp] at a [adj] | 10 |
|
| 7 | must [be] [verb] at an [adj] | 7 |
|
| 8 | must [be] [vb pp] at an [adj] | 6 |
|
| 9 | must [be] [vb pp] at an [adj] | 6 |
|
