| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [not/n't] prevent [pron] [prep] [verb] | 61 |
|
| 2 | [vb past] [not/n't] prevent [pron] [prep] | 32 |
|
| 3 | [vb past] [not/n't] prevent [pron] [verb] | 8 |
|
