| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which could [verb] | 1536 |
|
| 2 | which could [vb infin] | 1534 |
|
| 3 | [pron] could explain | 77 |
|
| 4 | which [modal v] explain | 74 |
|
| 5 | which could explain | 13 |
|
