| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [is] difficult [to-vb] | 1809 |
|
| 2 | it difficult [to-vb] [noun pl] | 56 |
|
| 3 | [is] difficult [to-vb] [noun pl] | 54 |
|
| 4 | it [is] [to-vb] [noun pl] | 52 |
|
