| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [adv] have [be] | 984 |
|
| 2 | could [adv] [be] [conj] | 73 |
|
| 3 | [adv] have [be] [conj] | 36 |
|
| 4 | could have [be] [conj] | 18 |
|
