| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] be on | 1824 |
|
| 2 | must be [prep] | 1101 |
|
| 3 | must be [prep] | 1101 |
|
| 4 | must [be] on | 128 |
|
| 5 | must be on | 128 |
|
