| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [adv] once a [noun] | 123 |
|
| 2 | [prep] [adv] once a [noun sg] | 123 |
|
| 3 | [prep] [adv] once a [noun] | 123 |
|
| 4 | [prep] [adv] once a [noun] | 122 |
|
| 5 | at [adv] once a [noun] | 118 |
|
| 6 | at [adv] once a [noun] | 118 |
|
| 7 | [prep] least once a [noun] | 118 |
|
| 8 | [prep] least once a [noun] | 118 |
|
| 9 | [prep] [adv] once a week | 49 |
|
| 10 | [prep] [adv] once a week | 49 |
|
| 11 | [prep] [adv] once a year | 33 |
|
| 12 | [prep] [adv] once a year | 33 |
|
| 13 | [prep] [adv] once a month | 17 |
|
| 14 | [prep] [adv] once a month | 17 |
|
| 15 | [prep] [adv] once a day | 11 |
|
| 16 | [prep] [adv] once a day | 11 |
|
| 17 | [prep] [adv] once a fortnight | 7 |
|
| 18 | [prep] [adv] once a fortnight | 7 |
|
