| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [adv] | 46692 |
|
| 2 | could [adv] | 17491 |
|
| 3 | [modal v] both | 489 |
|
| 4 | [vb mod] both | 489 |
|
| 5 | could both | 59 |
|
| 6 | could both | 59 |
|
