| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is [adv] [adv] difficult [verb] | 120 |
|
| 2 | it is [adv] [adv] difficult [verb] | 98 |
|
| 3 | it is often [adv] [adj] [verb] | 29 |
|
| 4 | it be often [adv] difficult [verb] | 12 |
|
| 5 | it [be] often [adv] difficult [verb] | 12 |
|
| 6 | it is often [adv] difficult [verb] | 11 |
|
| 7 | [pron] is often [adv] difficult [verb] | 11 |
|
| 8 | it [is] often [adv] difficult [verb] | 10 |
|
| 9 | it is often [adv] difficult [verb] | 10 |
|
