| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pron] could [vb infin] | 45138 |
|
| 2 | [vb past] [pron] [vb infin] | 20844 |
|
| 3 | [vb past] [pron] could | 2700 |
|
| 4 | [vb past] could [vb infin] | 53 |
|
