| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [adv] [verb] [prep] a | 169 |
|
| 2 | could [adv] have [verb] [prep] | 163 |
|
| 3 | [adv] have [verb] [prep] a | 108 |
|
| 4 | could have [verb] [prep] a | 76 |
|
| 5 | could [adv] have [verb] a | 48 |
|
