| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it 's [adv] difficult [to-vb] | 194 |
|
| 2 | but it 's [adv] difficult | 21 |
|
| 3 | but it 's difficult [to-vb] | 18 |
|
| 4 | but it 's [adv] [to-vb] | 6 |
|
