| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it 's difficult [to-vb] | 286 |
|
| 2 | it difficult [to-vb] [noun] | 119 |
|
| 3 | 's difficult [to-vb] [noun] | 24 |
|
| 4 | it 's [to-vb] [noun] | 16 |
|
