| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] difficult [to-vb] [prep] | 537 |
|
| 2 | [adv] [to-vb] them [prep] | 161 |
|
| 3 | [adv] difficult [to-vb] them | 37 |
|
| 4 | difficult [to-vb] them [prep] | 20 |
|
