| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is [adv] difficult for us | 5 |
|
| 2 | it is [adv] difficult for us | 5 |
|
| 3 | it is difficult for us [to-vb] | 12 |
|
| 4 | it is difficult for us [verb] | 12 |
|
