| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is difficult [to-vb] | 1523 |
|
| 2 | is difficult [to-vb] that | 97 |
|
| 3 | it difficult [to-vb] that | 41 |
|
| 4 | it is [to-vb] that | 37 |
|
