| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [adv] have be | 984 |
|
| 2 | [modal v] n't have be | 626 |
|
| 3 | could [not/n't] have be | 513 |
|
| 4 | could not have be | 513 |
|
| 5 | could n't [verb] be | 232 |
|
| 6 | could n't [vb infin] be | 232 |
|
| 7 | could n't have [be] | 185 |
|
| 8 | could n't have be | 185 |
|
