| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [is] difficult not [to-vb] | 32 |
|
| 2 | it [is] difficult not [verb] | 32 |
|
| 3 | it is difficult not [verb] | 28 |
|
| 4 | it [is] difficult not to see | 9 |
|
| 5 | it [is] difficult not see | 9 |
|
