| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is [adj] [to-vb] | 13509 |
|
| 2 | it [be] difficult [to-vb] | 2183 |
|
| 3 | it be difficult [to-vb] | 2183 |
|
| 4 | it [is] difficult [to-vb] | 1809 |
|
| 5 | [pron] is difficult [to-vb] | 1553 |
|
| 6 | it is difficult [verb] | 1529 |
|
| 7 | [pers pn] is difficult [to-vb] | 1527 |
|
| 8 | it is difficult [to-vb] | 1523 |
|
