| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is [adv] very difficult [verb] | 28 |
|
| 2 | it is [adv] very difficult [verb] | 27 |
|
| 3 | it is often [adv] difficult [verb] | 11 |
|
| 4 | it is often [adv] difficult [verb] | 10 |
|
| 5 | it is often very [adj] [verb] | 8 |
|
| 6 | [pron] is often very difficult [verb] | 8 |
|
| 7 | it be often very difficult [verb] | 7 |
|
| 8 | it is often very difficult [verb] | 7 |
|
| 9 | it is often very difficult [verb] | 7 |
|
| 10 | it [is] often very difficult [verb] | 7 |
|
| 11 | it [be] often very difficult [verb] | 7 |
|
