| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | at least [adv] a month [prep] | 7 |
|
| 2 | [prep] least [adv] a month [prep] | 7 |
|
| 3 | [prep] least [adv] a month [prep] | 7 |
|
| 4 | [prep] least once a month [prep] | 6 |
|
| 5 | [prep] least once a month [prep] | 6 |
|
