| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] difficult [to-vb] [conj] [art] | 107 |
|
| 2 | [be] very difficult [to-vb] [art] | 82 |
|
| 3 | [be] very difficult [to-vb] [conj] | 50 |
|
| 4 | very difficult [to-vb] [conj] [art] | 14 |
|
| 5 | [be] very difficult [conj] [art] | 7 |
|
