| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] once [prep] a [noun sg] | 34 |
|
| 2 | [verb] once in a [noun] | 15 |
|
| 3 | [vb past] once [prep] a [noun] | 12 |
|
| 4 | [vb pp] once [prep] a [noun] | 12 |
|
| 5 | [verb] once [prep] a while | 11 |
|
| 6 | [verb] once [prep] a while | 11 |
|
| 7 | [verb] once on a [noun] | 5 |
|
| 8 | [verb] once [prep] a time | 5 |
|
| 9 | [verb] once upon a [noun] | 5 |
|
| 10 | [verb] once [prep] a time | 5 |
|
| 11 | [vb base] once [prep] a [noun] | 5 |
|
