| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [is] [adv] difficult [to-vb] | 910 |
|
| 2 | [coord] it [is] difficult [to-vb] | 192 |
|
| 3 | [coord] it [is] [adv] difficult | 141 |
|
| 4 | [coord] it [is] [adv] [to-vb] | 19 |
|
| 5 | [coord] [is] [adv] difficult [to-vb] | 17 |
|
