| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they could [verb] | 4343 |
|
| 2 | they could [vb infin] | 4286 |
|
| 3 | [pron] could achieve | 70 |
|
| 4 | they [modal v] achieve | 69 |
|
| 5 | they [vb mod] achieve | 69 |
|
| 6 | they could achieve | 18 |
|
| 7 | they could achieve | 18 |
|
