| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adj] [to-vb] [is] [art] [adj] | 15 |
|
| 2 | difficult [to-vb] [be] [art] [adj] | 10 |
|
| 3 | difficult [verb] [is] [art] [adj] | 6 |
|
