| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [v-ing] [prep] twenty [noun pl] | 9 |
|
| 2 | have been [v-ing] for twenty [noun] | 9 |
|
| 3 | have been [v-ing] [prep] twenty year | 8 |
|
| 4 | have been [v-ing] [prep] twenty years | 8 |
|
