| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] [prep] once [prep] [art] | 31 |
|
| 2 | [vb past] at once [prep] [art] | 30 |
|
| 3 | [vb past] [prep] once [prep] the | 22 |
|
| 4 | [vb past] [prep] once to [art] | 11 |
|
| 5 | [vb past] [prep] once to [art] | 11 |
|
| 6 | [vb past] [prep] once [prep] a | 9 |
|
