| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it do n't happen | 102 |
|
| 2 | it [vb -s] n't happen | 57 |
|
| 3 | it does n't happen | 57 |
|
| 4 | it did n't happen | 45 |
|
| 5 | it [vb past] n't happen | 45 |
|
