| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] how difficult it [vb mod] | 20 |
|
| 2 | know how difficult it [vb mod] | 7 |
|
| 3 | [vb base] how difficult it [vb mod] | 7 |
|
| 4 | [vb past] how difficult it [vb mod] | 6 |
|
| 5 | how difficult it [vb mod] [be] | 25 |
|
| 6 | how difficult it [vb mod] [be] | 25 |
|
| 7 | how difficult it [vb mod] be | 25 |
|
| 8 | how difficult it [vb mod] be | 25 |
|
