| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | difficult [to-vb] [det] [noun] [prep] | 94 |
|
| 2 | it difficult [to-vb] [noun] [prep] | 44 |
|
| 3 | it difficult [to-vb] [det] [noun] | 20 |
|
| 4 | it [to-vb] [det] [noun] [prep] | 15 |
|
| 5 | it difficult [to-vb] [det] [prep] | 10 |
|
