| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [vb infin] been [vb pp] [adj] | 24 |
|
| 2 | could have be [vb pp] [adj] | 23 |
|
| 3 | could [vb infin] be [vb pp] [adj] | 12 |
|
| 4 | could [vb infin] be [vb pp] [det] | 7 |
|
| 5 | could [vb infin] be [vb pp] [num] | 5 |
|
