| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [v-ing] [verb] a | 816 |
|
| 2 | [prep] [v-ing] [been] [verb] | 187 |
|
| 3 | [v-ing] [been] [verb] a | 23 |
|
| 4 | [prep] [v-ing] [been] a | 13 |
|
