| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [vb infin] [prep] | 9758 |
|
| 2 | [vb infin] [vb pp] [prep] | 9075 |
|
| 3 | could [vb infin] [vb pp] | 5483 |
|
| 4 | could [vb pp] [prep] | 7 |
|
