| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it be [prep] [v-ing] | 2114 |
|
| 2 | it be [prep] a | 2077 |
|
| 3 | be [prep] [v-ing] a | 559 |
|
| 4 | it be [v-ing] a | 447 |
|
| 5 | it [prep] [v-ing] a | 81 |
|
