| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [not/n't] [verb] for certain | 30 |
|
| 2 | [not/n't] [vb infin] for certain | 23 |
|
| 3 | [not/n't] know for certain | 20 |
|
| 4 | not [verb] for certain | 15 |
|
| 5 | n't [verb] for certain | 15 |
|
| 6 | [not/n't] know for certain | 13 |
|
| 7 | [not/n't] say for certain | 8 |
|
| 8 | [not/n't] say for certain | 8 |
|
| 9 | [not/n't] known for certain | 7 |
|
| 10 | [not/n't] [vb pp] for certain | 7 |
|
