| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] [vb infin] [be] [conj] | 551 |
|
| 2 | [modal v] [vb infin] [be] [conj] | 551 |
|
| 3 | must [vb infin] [be] [conj] | 41 |
|
| 4 | must [verb] [be] [conj] | 41 |
|
