| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [be] [verb] [prep] [art] [noun] | 1375 |
|
| 2 | [modal v] [be] [v-ing] [prep] [art] [noun] | 976 |
|
| 3 | must [be] [v-ing] [prep] [art] [noun] | 32 |
|
| 4 | must [be] [v-ing] [prep] [art] [noun] | 32 |
|
