| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh det] could [vb infin] to be | 7 |
|
| 2 | which could [verb] to be | 5 |
|
| 3 | [Wh det] could prove to be | 5 |
|
| 4 | [Wh det] could prove to be | 5 |
|
