| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] but once a | 5 |
|
| 2 | but once a [noun] | 16 |
|
| 3 | but once a [noun sg] | 16 |
|
| 4 | but once a year | 7 |
|
| 5 | but once a year | 7 |
|
