| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which [vb mod] to be | 130 |
|
| 2 | which [vb mod] [prep] be | 130 |
|
| 3 | which used [prep] be | 69 |
|
| 4 | which ought [prep] be | 61 |
|
