| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is [prep] [v-ing] | 1207 |
|
| 2 | it is [prep] a | 379 |
|
| 3 | is [prep] [v-ing] a | 184 |
|
| 4 | it is [v-ing] a | 126 |
|
| 5 | it [prep] [v-ing] a | 69 |
|
