| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] [adv] [prep] a | 8226 |
|
| 2 | [adv] once [prep] a | 40 |
|
| 3 | [vb past] [adv] once [prep] | 24 |
|
| 4 | [vb past] once [prep] a | 13 |
|
| 5 | [vb past] [adv] once a | 10 |
|
