| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [subord] it [is] [adv] [adj] [verb] | 450 |
|
| 2 | [conj] it [is] [adv] difficult [verb] | 217 |
|
| 3 | [subord] it [be] [adv] difficult [verb] | 58 |
|
| 4 | [subord] [pron] [is] [adv] difficult [verb] | 51 |
|
