| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they could [vb infin] [verb] [noun sg] | 20 |
|
| 2 | they could [verb] [vb pp] [noun sg] | 12 |
|
| 3 | they could have [verb] [noun sg] | 12 |
|
| 4 | they could have [verb] [noun sg] | 12 |
|
| 5 | they could [verb] [to-vb] [noun sg] | 8 |
|
