| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [coord] [prep] a period of time | 13 |
|
| 2 | [coord] [prep] a period [prep] time | 13 |
|
| 3 | [coord] [prep] a period of time | 13 |
|
| 4 | [coord] [prep] a period [prep] time | 13 |
|
| 5 | [coord] over a period [prep] time | 11 |
|
| 6 | and [prep] a period [prep] time | 9 |
|
