| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it 's [adj] [to-vb] [noun] | 251 |
|
| 2 | it be difficult [to-vb] [noun] | 169 |
|
| 3 | it [be] difficult [to-vb] [noun] | 169 |
|
| 4 | it [is] difficult [to-vb] [noun] | 142 |
|
| 5 | [pers pn] 's difficult [to-vb] [noun] | 24 |
|
| 6 | it 's difficult [to-vb] [noun] | 24 |
|
| 7 | [pron] 's difficult [to-vb] [noun] | 24 |
|
| 8 | it 's difficult [verb] [noun] | 24 |
|
