| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it be [v-ing] na | 751 |
|
| 2 | it [be] [v-ing] na | 751 |
|
| 3 | it [is] [v-ing] na | 675 |
|
| 4 | it is [v-ing] [prep] | 539 |
|
| 5 | [pron] is [v-ing] na | 58 |
|
| 6 | it is [verb] na | 15 |
|
