| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | who have been working | 39 |
|
| 2 | [Wh pn] had been working | 16 |
|
| 3 | [Wh pn] has been working | 10 |
|
| 4 | [Wh pn] have been working | 8 |
|
