| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [adv] difficult [to-vb] | 825 |
|
| 2 | [adv] difficult [to-vb] [coord] | 136 |
|
| 3 | is [adv] difficult [coord] | 46 |
|
| 4 | is difficult [to-vb] [coord] | 44 |
|
| 5 | is [adv] [to-vb] [coord] | 38 |
|
