| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | how difficult it can [be] [verb] | 7 |
|
| 2 | [Wh adv] difficult it can [be] [verb] | 7 |
|
| 3 | [Wh adv] difficult it can be [verb] | 7 |
|
| 4 | [Wh adv] difficult it can [be] [to-vb] | 6 |
|
