| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [art] [noun] once a | 26 |
|
| 2 | [prep] [art] [noun sg] once a | 20 |
|
| 3 | [prep] [art] [noun pl] once a | 5 |
|
| 4 | [prep] [art] once a [noun sg] | 6 |
|
| 5 | [prep] [art] once a [noun] | 6 |
|
