| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] could [vb infin] | 53 |
|
| 2 | [vb past] could have | 10 |
|
| 3 | [vb past] could have | 10 |
|
| 4 | knew could [verb] | 8 |
|
| 5 | said could [verb] | 6 |
|
| 6 | did could [verb] | 5 |
|
