| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] have [been] [det] | 361 |
|
| 2 | could have [been] [adj] | 346 |
|
| 3 | could [vb infin] [been] [det] | 63 |
|
| 4 | could have [been] [det] | 63 |
|
| 5 | could [verb] [been] [det] | 63 |
|
| 6 | could have [be] [det] | 62 |
|
