| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] difficult [to-vb] | 3329 |
|
| 2 | [adv] [to-vb] that | 1263 |
|
| 3 | difficult [to-vb] that | 278 |
|
| 4 | [adv] difficult that | 17 |
|
