| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] not have known | 139 |
|
| 2 | would not have known | 75 |
|
| 3 | [vb mod] n't have known | 74 |
|
| 4 | [vb mod] not have known | 65 |
|
| 5 | could not have known | 41 |
|
| 6 | may not have known | 8 |
|
| 7 | might not have known | 7 |
|
| 8 | should not have known | 5 |
|
