| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they could [not/n't] [vb infin] | 1283 |
|
| 2 | [vb past] they could [vb infin] | 182 |
|
| 3 | [vb past] they could [not/n't] | 90 |
|
| 4 | [vb past] they [not/n't] [vb infin] | 23 |
|
| 5 | [vb past] could [not/n't] [vb infin] | 20 |
|
