| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [not/n't] [vb infin] | 21338 |
|
| 2 | [not/n't] [vb infin] [noun] | 16919 |
|
| 3 | could [vb infin] [noun] | 5118 |
|
| 4 | could [not/n't] [noun] | 78 |
|
