| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | difficult [to-vb] [conj] | 1092 |
|
| 2 | more difficult [to-vb] | 810 |
|
| 3 | more difficult [conj] | 315 |
|
| 4 | more [to-vb] [conj] | 43 |
|
