| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | do [not/n't] [vb infin] for certain | 12 |
|
| 2 | do [not/n't] know for certain | 11 |
|
| 3 | do [not/n't] know for certain | 11 |
|
| 4 | do [not/n't] [verb] for certain | 10 |
|
| 5 | do n't [verb] for certain | 8 |
|
