| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] which could | 2160 |
|
| 2 | problem which [modal v] | 155 |
|
| 3 | problem which [vb mod] | 155 |
|
| 4 | problem [pron] could | 31 |
|
| 5 | problem which could | 19 |
|
