| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [not/n't] known for certain | 7 |
|
| 2 | be [not/n't] know for certain | 7 |
|
| 3 | be not [verb] for certain | 7 |
|
| 4 | be [not/n't] [vb pp] for certain | 7 |
|
| 5 | is [not/n't] [verb] for certain | 6 |
|
