| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [not/n't] [verb] [prep] | 2121 |
|
| 2 | could [not/n't] [vb infin] [prep] | 2115 |
|
| 3 | [modal v] [not/n't] know [prep] | 80 |
|
| 4 | could [adv] know [prep] | 9 |
|
| 5 | could [not/n't] know [prep] | 7 |
|
| 6 | could [not/n't] know [prep] | 7 |
|
