| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [not/n't] be | 3440 |
|
| 2 | could have be | 2482 |
|
| 3 | [not/n't] have be | 2176 |
|
| 4 | could [not/n't] have | 1780 |
|
