| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] not [be] [vb pp] | 15684 |
|
| 2 | could [adv] [be] [vb pp] | 4743 |
|
| 3 | could not [be] [verb] | 2288 |
|
| 4 | could not [be] [vb pp] | 2251 |
|
