| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb base] [pron] could [vb infin] | 1156 |
|
| 2 | [vb base] they [modal v] [vb infin] | 1039 |
|
| 3 | [verb] they could [vb infin] | 367 |
|
| 4 | [vb base] they could [verb] | 64 |
|
