| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [verb] on at | 17 |
|
| 2 | have been [v-ing] on at | 10 |
|
| 3 | have been going on at | 9 |
|
| 4 | have been go on at | 9 |
|
| 5 | has been [verb] on at | 8 |
|
| 6 | have been [vb pp] on at | 7 |
|
