| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [prep] a month [prep] | 12 |
|
| 2 | [prep] [prep] a month [prep] | 12 |
|
| 3 | for [prep] a month [prep] | 9 |
|
| 4 | [prep] about a month [prep] | 7 |
|
| 5 | [prep] about a month [prep] | 7 |
|
