| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb base] [Wh adv] difficult it is for | 7 |
|
| 2 | [vb base] how difficult it is for | 7 |
|
| 3 | [vb base] [Wh adv] difficult it is for | 7 |
|
| 4 | know [Wh adv] difficult it is for | 5 |
|
