| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [not/n't] [vb infin] | 21338 |
|
| 2 | [conj] could [vb infin] | 2359 |
|
| 3 | [conj] could [not/n't] | 1345 |
|
| 4 | [conj] [not/n't] [vb infin] | 86 |
|
