| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [adv] [adv] difficult [to-vb] | 168 |
|
| 2 | is [adv] difficult [to-vb] that | 30 |
|
| 3 | is [adv] [adv] [to-vb] that | 26 |
|
| 4 | is [adv] difficult [to-vb] that | 15 |
|
| 5 | [adv] [adv] difficult [to-vb] that | 10 |
|
