| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [det] [prep] once [art] | 29 |
|
| 2 | [det] at once [art] | 28 |
|
| 3 | all [prep] once [art] | 28 |
|
| 4 | [det] [prep] once the | 17 |
|
| 5 | [det] [prep] once the | 17 |
|
| 6 | [det] [prep] once a | 12 |
|
| 7 | [det] [prep] once a | 10 |
|
