| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [not/n't] [vb infin] | 21338 |
|
| 2 | [not/n't] [pron] [vb infin] | 7685 |
|
| 3 | could [pron] [vb infin] | 3881 |
|
| 4 | could [not/n't] [pron] | 886 |
|
