| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which have been [verb] for a | 14 |
|
| 2 | [Wh det] have been [vb pp] for a | 9 |
|
| 3 | [Wh det] has been [verb] for a | 7 |
|
| 4 | [Wh det] had been [verb] for a | 6 |
|
| 5 | [Wh det] have been [v-ing] for a | 5 |
|
