| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they could [verb] [pron] | 669 |
|
| 2 | they could [vb infin] [pron] | 657 |
|
| 3 | [pron] could do [pron] | 566 |
|
| 4 | they [modal v] do [pron] | 366 |
|
| 5 | they could do [pron] | 66 |
|
