| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which be at once | 14 |
|
| 2 | which [be] at once | 14 |
|
| 3 | which is at once | 9 |
|
| 4 | which [is] at once | 9 |
|
| 5 | which at once [verb] | 9 |
|
| 6 | which at once [vb past] | 5 |
|
