| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must be [vb pp] [subord] | 499 |
|
| 2 | must be [vb pp] [adj] | 218 |
|
| 3 | be [vb pp] [adj] [subord] | 161 |
|
| 4 | must be [adj] [subord] | 102 |
|
