| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [verb] for twenty year | 9 |
|
| 2 | have been [verb] for twenty years | 9 |
|
| 3 | have been [v-ing] for twenty year | 8 |
|
| 4 | has been [verb] for twenty year | 5 |
|
