| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [not/n't] [vb infin] for certain [pron] | 7 |
|
| 2 | [not/n't] [verb] for certain [Wh det] | 6 |
|
| 3 | [not/n't] [verb] for certain what | 6 |
|
| 4 | [not/n't] [verb] for certain what | 6 |
|
