| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | difficult [to-vb] [conj] [art] [noun] | 144 |
|
| 2 | [adj] [to-vb] [coord] [art] [noun] | 92 |
|
| 3 | difficult [verb] [coord] [art] [noun] | 18 |
|
| 4 | difficult [to-vb] [coord] [art] [noun] | 18 |
|
