| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] [vb pp] a [noun sg] | 839 |
|
| 2 | must [be] a [noun sg] | 605 |
|
| 3 | must [be] [vb pp] a | 53 |
|
| 4 | must [be] [vb pp] [noun sg] | 39 |
|
