| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] at least once [art] | 24 |
|
| 2 | [vb pp] at [adv] once [art] | 24 |
|
| 3 | [vb pp] at [adv] once a | 19 |
|
| 4 | [vb pp] at [adv] once a | 19 |
|
| 5 | [vb pp] at [adv] once every | 5 |
|
| 6 | [vb pp] at [adv] once every | 5 |
|
