| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [adv] have [vb pp] [prep] | 163 |
|
| 2 | could n't have [vb pp] [prep] | 89 |
|
| 3 | could n't [adv] have [vb pp] | 39 |
|
| 4 | n't [adv] have [vb pp] [prep] | 14 |
|
