| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] could be | 102 |
|
| 2 | [be] [vb pp] could | 77 |
|
| 3 | [be] could be | 24 |
|
| 4 | [be] [vb pp] be | 19 |
|
