| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [subord] it is difficult [prep] | 20 |
|
| 2 | [subord] it is difficult [prep] | 20 |
|
| 3 | [subord] it is difficult for | 13 |
|
| 4 | [subord] it is difficult for | 13 |
|
| 5 | [subord] it is difficult to | 6 |
|
| 6 | [subord] it is difficult to | 6 |
|
