| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had been [v-ing] [prep] | 1917 |
|
| 2 | had been [v-ing] [det] | 175 |
|
| 3 | been [v-ing] [det] [prep] | 126 |
|
| 4 | had been [det] [prep] | 31 |
|
