| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is [adj] to understand [Wh adv] | 63 |
|
| 2 | it [adj] to understand [Wh adv] [pers pn] | 8 |
|
| 3 | it is [adj] [Wh adv] [pers pn] | 8 |
|
| 4 | is [adj] to understand [Wh adv] [pers pn] | 7 |
|
