| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] a [noun] | 76638 |
|
| 2 | [adv] a [noun] | 47639 |
|
| 3 | once [art] [noun] | 2240 |
|
| 4 | once a [noun] | 1633 |
|
