| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [noun] [art] | 2299 |
|
| 2 | once [prep] a [noun] | 401 |
|
| 3 | once a [noun] [art] | 19 |
|
| 4 | once [prep] [noun] [art] | 14 |
|
