| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [verb] for decades | 14 |
|
| 2 | [verb] been [verb] for decades | 14 |
|
| 3 | had been [verb] for decades | 5 |
|
| 4 | [vb past] been [verb] for decades | 5 |
|
| 5 | been [verb] [adv] for decades | 5 |
|
| 6 | been [verb] for [adj] decades | 5 |
|
