| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | when it was [verb] | 762 |
|
| 2 | when it was [vb pp] | 714 |
|
| 3 | [conj] it was discovered | 66 |
|
| 4 | when it be discovered | 31 |
|
| 5 | when it [be] discovered | 31 |
|
| 6 | when [pron] was discovered | 29 |
|
| 7 | when it was discover | 27 |
|
| 8 | when it [was/were] discovered | 27 |
|
