| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [was/were] [vb pp] on an [noun sg] | 55 |
|
| 2 | was [vb pp] on an [noun] | 43 |
|
| 3 | [was/were] based on an [noun] | 17 |
|
| 4 | were [vb pp] on an [noun] | 15 |
|
