| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is [adv] difficult [verb] | 558 |
|
| 2 | but it is [adv] [verb] | 200 |
|
| 3 | but it is difficult [verb] | 76 |
|
| 4 | but it is [adv] difficult | 35 |
|
