| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [not/n't] be [vb pp] | 2251 |
|
| 2 | could have be [vb pp] | 1057 |
|
| 3 | could [not/n't] have [vb pp] | 1018 |
|
| 4 | [not/n't] have be [vb pp] | 657 |
|
| 5 | could [not/n't] have be | 513 |
|
