| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [to-vb] [adv prt] [prep] a time | 10 |
|
| 2 | [to-vb] [adv] [prep] a time | 7 |
|
| 3 | [to-vb] [adv] at a time | 6 |
|
