| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] be [v-ing] | 7817 |
|
| 2 | [prep] [v-ing] at | 2878 |
|
| 3 | [prep] be at | 910 |
|
| 4 | be [v-ing] at | 857 |
|
