| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [adv] difficult [to-vb] the | 103 |
|
| 2 | is [adv] difficult [to-vb] the | 84 |
|
| 3 | is often [adj] [to-vb] the | 54 |
|
| 4 | is often [adj] [to-vb] the | 49 |
|
| 5 | is often difficult [to-vb] [art] | 18 |
|
| 6 | [be] often difficult [to-vb] the | 16 |
|
| 7 | be often difficult [to-vb] the | 16 |
|
| 8 | [is] often difficult [to-vb] the | 13 |
|
| 9 | is often difficult [to-vb] the | 13 |
|
| 10 | is often difficult [verb] the | 13 |
|
| 11 | is often difficult [to-vb] the | 13 |
|
