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