| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] difficult it is [v-ing] | 6 |
|
| 2 | [Wh adv] difficult it is [v-ing] | 5 |
|
| 3 | how difficult it is [v-ing] | 5 |
|
| 4 | how difficult it is [v-ing] | 5 |
|
