| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | difficult [to-vb] [conj] [art] | 200 |
|
| 2 | more difficult [to-vb] [conj] | 146 |
|
| 3 | more difficult [to-vb] [art] | 94 |
|
| 4 | more difficult [conj] [art] | 35 |
|
| 5 | more [to-vb] [conj] [art] | 13 |
|
