| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [verb] [prep] a | 4621 |
|
| 2 | once [verb] [prep] a | 219 |
|
| 3 | [prep] once [verb] [prep] | 93 |
|
| 4 | [prep] once [prep] a | 63 |
|
| 5 | [prep] once [verb] a | 26 |
|
