| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [vb pp] to be | 180 |
|
| 2 | have been shown to be | 62 |
|
| 3 | have been found to be | 47 |
|
| 4 | have been held to be | 10 |
|
| 5 | have been reported to be | 7 |
|
| 6 | have been proved to be | 5 |
|
