| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [adv] difficult [verb] [coord] | 32 |
|
| 2 | is [adv] difficult [to-vb] [coord] | 32 |
|
| 3 | is [adv] difficult [verb] and | 22 |
|
| 4 | is [adv] difficult [verb] but | 7 |
|
| 5 | is more difficult [verb] [coord] | 6 |
|
| 6 | is notoriously difficult [verb] [coord] | 5 |
|
