| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have [been] [vb pp] | 1042 |
|
| 2 | could have [vb pp] [art] | 817 |
|
| 3 | could have [been] [art] | 361 |
|
| 4 | have [been] [vb pp] [art] | 147 |
|
