| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | who had been [v-ing] [prep] | 160 |
|
| 2 | [n mass] who had been [prep] | 23 |
|
| 3 | [n mass] had been [v-ing] [prep] | 14 |
|
| 4 | [n mass] who had been [v-ing] | 11 |
|
