| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is difficult [to-vb] | 1523 |
|
| 2 | is difficult [to-vb] [coord] | 44 |
|
| 3 | it difficult [to-vb] [coord] | 21 |
|
| 4 | it is [to-vb] [coord] | 20 |
|
| 5 | it is difficult [coord] | 14 |
|
