| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is difficult [verb] a [noun] | 41 |
|
| 2 | is [verb] such a [noun] | 20 |
|
| 3 | difficult [verb] such a [noun] | 11 |
|
| 4 | is difficult [verb] such [noun] | 8 |
|
| 5 | is difficult [verb] such a | 5 |
|
