| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] [vb pp] [prep] a time | 18 |
|
| 2 | [adv] [vb pp] [prep] a time | 18 |
|
| 3 | [adv] [vb pp] at a time | 9 |
|
| 4 | [adv] [vb pp] at a time | 9 |
|
