| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [verb] [det] [adj] [noun] | 243 |
|
| 2 | is difficult [verb] [adj] [noun] | 128 |
|
| 3 | difficult [verb] [det] [adj] [noun] | 69 |
|
| 4 | is difficult [verb] [det] [noun] | 64 |
|
| 5 | is difficult [verb] [det] [adj] | 31 |
|
