| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | has been [verb] [prep] three years | 18 |
|
| 2 | [vb -s] been [verb] for three years | 17 |
|
| 3 | [vb -s] been [vb pp] [prep] three years | 11 |
|
| 4 | [vb -s] been [v-ing] [prep] three years | 8 |
|
