| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it be difficult [to-vb] | 2183 |
|
| 2 | be difficult [to-vb] [adj] | 325 |
|
| 3 | it be [to-vb] [adj] | 241 |
|
| 4 | it difficult [to-vb] [adj] | 118 |
|
| 5 | it be difficult [adj] | 5 |
|
