| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had been [v-ing] on [noun] | 31 |
|
| 2 | had been [v-ing] on [noun sg] | 17 |
|
| 3 | had been working on [noun] | 9 |
|
| 4 | had been [v-ing] on [noun pl] | 7 |
|
| 5 | had been [v-ing] on [noun prp] | 6 |
|
