| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] difficult [to-vb] | 3607 |
|
| 2 | not [adv] [to-vb] | 1546 |
|
| 3 | not difficult [to-vb] | 250 |
|
| 4 | not [adv] difficult | 139 |
|
