| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | how difficult it is [prep] | 21 |
|
| 2 | [Wh adv] difficult it is [prep] | 21 |
|
| 3 | [Wh adv] difficult it is [prep] | 21 |
|
| 4 | [Wh adv] difficult it is for | 17 |
|
| 5 | [Wh adv] difficult it is for | 17 |
|
