| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | at a time [prep] | 476 |
|
| 2 | [adv] at a time | 116 |
|
| 3 | [adv] a time [prep] | 38 |
|
| 4 | [adv] at time [prep] | 25 |
|
