| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had been working on | 46 |
|
| 2 | have been working on | 38 |
|
| 3 | has been working on | 34 |
|
| 4 | 've been working on | 30 |
|
| 5 | 'd been working on | 7 |
|
| 6 | have been working on | 7 |
|
