| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] once the | 66 |
|
| 2 | [vb pp] once [art] | 32 |
|
| 3 | [to-vb] once [art] | 15 |
|
| 4 | [verb] once a | 11 |
|
| 5 | [v-ing] once [art] | 11 |
|
| 6 | [vb -s] once [art] | 10 |
|
| 7 | [vb infin] once [art] | 7 |
|
| 8 | [vb base] once [art] | 7 |
|
| 9 | [verb] once an | 7 |
|
| 10 | leave once [art] | 5 |
|
