| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] once to a | 7 |
|
| 2 | [prep] once to a | 7 |
|
| 3 | at once to a | 7 |
|
| 4 | at once to a | 7 |
|
| 5 | once [verb] to a | 30 |
|
| 6 | once [vb pp] to a | 15 |
|
| 7 | once [vb past] to a | 14 |
|
| 8 | once belong to a | 5 |
|
| 9 | once to a [noun] | 6 |
|
| 10 | once to a [noun sg] | 6 |
|
