| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [conj] it is sometimes difficult [verb] | 7 |
|
| 2 | it is sometimes difficult [verb] [art] | 5 |
|
| 3 | it is sometimes difficult [verb] [art] | 5 |
|
| 4 | it is sometimes difficult [verb] [conj] | 5 |
|
