| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which have been [verb] for [det] | 21 |
|
| 2 | which had been [verb] for [det] | 13 |
|
| 3 | which have been [vb pp] for [det] | 13 |
|
| 4 | which have been [verb] for many | 10 |
|
| 5 | which have been [v-ing] for [det] | 8 |
|
| 6 | which have been [verb] for some | 6 |
|
| 7 | which has been [verb] for [det] | 6 |
|
