| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | been [v-ing] [prep] | 6841 |
|
| 2 | had been [v-ing] | 5819 |
|
| 3 | had been [prep] | 3635 |
|
| 4 | had [v-ing] [prep] | 21 |
|
