| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it could [not/n't] [vb infin] | 469 |
|
| 2 | [vb past] it could [vb infin] | 81 |
|
| 3 | [vb past] it could [not/n't] | 68 |
|
| 4 | [vb past] could [not/n't] [vb infin] | 20 |
|
| 5 | [vb past] it [not/n't] [vb infin] | 13 |
|
