| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] it a difficult [noun] | 6 |
|
| 2 | it be a difficult [noun] | 108 |
|
| 3 | it [be] a difficult [noun] | 108 |
|
| 4 | it [is] a difficult [noun] | 66 |
|
| 5 | it was a difficult [noun] | 42 |
|
| 6 | it [was/were] a difficult [noun] | 42 |
|
| 7 | it 's a difficult [noun] | 36 |
|
| 8 | it is a difficult [noun] | 30 |
|
