| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [v-ing] [prep] a | 98 |
|
| 2 | they have been [v-ing] [prep] | 52 |
|
| 3 | they have been [prep] a | 12 |
|
| 4 | they have been [v-ing] a | 10 |
|
