| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | who could [verb] | 1259 |
|
| 2 | who could [vb infin] | 1251 |
|
| 3 | [pron] could use | 495 |
|
| 4 | who [modal v] use | 73 |
|
| 5 | who could use | 9 |
|
