| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [to-vb] [conj] it is | 711 |
|
| 2 | difficult [to-vb] [conj] it | 60 |
|
| 3 | difficult [conj] it is | 24 |
|
| 4 | difficult [to-vb] [conj] is | 8 |
|
