| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] [adv] [vb infin] | 60233 |
|
| 2 | could [adv] [vb infin] | 32770 |
|
| 3 | [vb past] could [adv] | 58 |
|
| 4 | [vb past] could [vb infin] | 53 |
|
