| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is [adv] difficult [to-vb] | 554 |
|
| 2 | is [adv] difficult [to-vb] [coord] | 32 |
|
| 3 | it [adv] difficult [to-vb] [coord] | 10 |
|
| 4 | it is [adv] difficult [coord] | 10 |
|
| 5 | it is difficult [to-vb] [coord] | 8 |
|
