| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] once in a [noun sg] | 15 |
|
| 2 | [vb past] once [prep] a [noun sg] | 12 |
|
| 3 | [verb] once [prep] a while | 11 |
|
| 4 | [vb pp] once [prep] a [noun sg] | 10 |
|
| 5 | [vb base] once [prep] a [noun sg] | 5 |
|
| 6 | [verb] once upon a [noun sg] | 5 |
|
| 7 | [verb] once [prep] a time | 5 |
|
