| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have [vb pp] [adj] | 517 |
|
| 2 | could [pron] have [vb pp] | 282 |
|
| 3 | [pron] have [vb pp] [adj] | 94 |
|
| 4 | could [pron] have [adj] | 40 |
|
