| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [verb] be [vb pp] up | 16 |
|
| 2 | could have be [vb pp] up | 16 |
|
| 3 | could [vb infin] be [vb pp] up | 16 |
|
| 4 | could have be [vb pp] up | 16 |
|
| 5 | could [verb] been [vb pp] up | 16 |
|
