| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | who had [been] working [prep] | 12 |
|
| 2 | who had [be] working [prep] | 12 |
|
| 3 | who had be working [prep] | 12 |
|
| 4 | who had been working [prep] | 12 |
|
| 5 | who had [be] working in | 5 |
|
