| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which had been [vb pp] for | 76 |
|
| 2 | [Wh det] had been used for | 10 |
|
| 3 | [Wh det] had been scheduled for | 7 |
|
| 4 | what had been [vb pp] for | 7 |
|
