| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have [been] [vb pp] [prep] | 3659 |
|
| 2 | could have [been] [vb pp] | 1042 |
|
| 3 | could have [vb pp] [prep] | 862 |
|
| 4 | could have [been] [prep] | 99 |
|
