| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [not/n't] have [vb pp] [art] | 157 |
|
| 2 | [not/n't] have [vb pp] [art] [adj -er] | 43 |
|
| 3 | could have [vb pp] [art] [adj -er] | 21 |
|
| 4 | could [not/n't] have [art] [adj -er] | 10 |
|
