| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | been [v-ing] [prep] a | 665 |
|
| 2 | have been [v-ing] [prep] | 336 |
|
| 3 | have been [prep] a | 123 |
|
| 4 | have been [v-ing] a | 65 |
|
