| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a period | 2139 |
|
| 2 | [prep] a period | 2137 |
|
| 3 | over a period | 682 |
|
| 4 | for a period | 518 |
|
| 5 | in a period | 180 |
|
| 6 | after a period | 175 |
|
| 7 | during a period | 110 |
|
| 8 | of a period | 74 |
|
| 9 | to a period | 63 |
|
| 10 | through a period | 55 |
|
| 11 | with a period | 54 |
|
| 12 | within a period | 50 |
|
| 13 | as a period | 41 |
|
| 14 | by a period | 37 |
|
| 15 | from a period | 27 |
|
| 16 | at a period | 17 |
|
| 17 | on a period | 13 |
|
| 18 | into a period | 11 |
|
| 19 | before a period | 6 |
|
| 20 | about a period | 6 |
|
