| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] [prep] course be | 203 |
|
| 2 | [vb mod] [prep] course be | 203 |
|
| 3 | must [prep] [noun] be | 65 |
|
| 4 | must [prep] course [be] | 29 |
|
| 5 | must [prep] course be | 29 |
|
