| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] [prep] a [noun] | 174585 |
|
| 2 | once [prep] a [noun] | 401 |
|
| 3 | [noun] once a [noun] | 298 |
|
| 4 | [noun] once [prep] a | 41 |
|
| 5 | [noun] once [prep] [noun] | 37 |
|
