| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had been [v-ing] for years | 18 |
|
| 2 | been [v-ing] for many years | 14 |
|
| 3 | had been [v-ing] for many | 8 |
|
| 4 | had been for many years | 7 |
|
