| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] [v-ing] [prep] a | 7866 |
|
| 2 | [prep] [v-ing] [prep] a | 4345 |
|
| 3 | [be] [prep] [v-ing] [prep] | 953 |
|
| 4 | [be] [prep] [v-ing] a | 559 |
|
| 5 | [be] [prep] [prep] a | 70 |
|
