| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it difficult for [noun] [noun] | 8 |
|
| 2 | it difficult [prep] [noun] [noun] | 8 |
|
| 3 | it difficult [prep] [noun sg] [noun] | 7 |
|
| 4 | it difficult [prep] [noun] [noun pl] | 6 |
|
