| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [was/were] [prep] a | 5878 |
|
| 2 | once [prep] a | 498 |
|
| 3 | [was/were] once a | 240 |
|
| 4 | [was/were] once [prep] | 52 |
|
