| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [adv] [prep] a time | 21 |
|
| 2 | at [adv] [prep] a time | 16 |
|
| 3 | at [adv] [prep] a time | 16 |
|
| 4 | [prep] [adv] for a time | 16 |
|
| 5 | [prep] least [prep] a time | 15 |
|
