| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | once [adv] at a | 6 |
|
| 2 | once [adv] at a | 6 |
|
| 3 | once [verb] at a | 5 |
|
| 4 | once at a [noun sg] | 5 |
|
| 5 | once at a [noun] | 5 |
|
