| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is [adv] [v-ing] [prep] | 145 |
|
| 2 | [subord] it is [adv] [prep] | 135 |
|
| 3 | [subord] it is [v-ing] [prep] | 80 |
|
| 4 | [subord] it is [adv] [v-ing] | 56 |
|
| 5 | [subord] is [adv] [v-ing] [prep] | 8 |
|
