| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb -s] [conj] once a | 9 |
|
| 2 | [vb -s] [that] once a | 7 |
|
| 3 | [vb -s] that once a | 7 |
|
| 4 | [vb -s] that once a | 7 |
|
