| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | once a [noun sg] | 1545 |
|
| 2 | once a week | 483 |
|
| 3 | once a year | 253 |
|
| 4 | once a month | 199 |
|
| 5 | once a day | 79 |
|
| 6 | once a fortnight | 76 |
|
| 7 | once an [noun sg] | 61 |
|
| 8 | once a quarter | 9 |
|
| 9 | once a member | 9 |
|
| 10 | once a person | 9 |
|
| 11 | once a woman | 7 |
|
| 12 | once a term | 7 |
|
| 13 | once a man | 7 |
|
| 14 | once a student | 6 |
|
