| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] difficult [coord] | 300 |
|
| 2 | [adv] difficult to understand | 62 |
|
| 3 | difficult to understand [coord] | 20 |
|
| 4 | [adv] to understand [coord] | 9 |
|
