| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [is] often [adj] [verb] [subord] | 6 |
|
| 2 | it [is] often [adj] [verb] [subord] | 6 |
|
| 3 | it [is] often difficult [verb] [subord] | 5 |
|
| 4 | it [is] often difficult [verb] [subord] | 5 |
|
| 5 | it [is] often [verb] that [subord] | 7 |
|
| 6 | it [is] often [verb] that [subord] | 7 |
|
| 7 | it [is] often [verb] [that] [subord] | 7 |
|
| 8 | it [is] often [verb] [conj] [subord] | 7 |
|
