| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] difficult [to-vb] an | 37 |
|
| 2 | very difficult [to-vb] an | 14 |
|
| 3 | more difficult [to-vb] an | 7 |
|
| 4 | [adv] difficult to find an | 5 |
|
