| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it be [prep] | 23915 |
|
| 2 | it be [v-ing] | 10694 |
|
| 3 | be [prep] [v-ing] | 5741 |
|
| 4 | it [prep] [v-ing] | 1118 |
|
