| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] once [prep] a | 40 |
|
| 2 | [adv] once [prep] a | 39 |
|
| 3 | [adv] once [prep] a | 31 |
|
| 4 | [adv] once in a | 27 |
|
| 5 | [adv prt] once [prep] a | 9 |
|
| 6 | only once [prep] a | 6 |
|
| 7 | least once [prep] a | 6 |
|
| 8 | least once [prep] a | 6 |
|
| 9 | only once [prep] a | 6 |
|
