| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] [prep] a period [prep] | 93 |
|
| 2 | [adv] [prep] a period [prep] | 93 |
|
| 3 | [adv] [prep] a period of | 87 |
|
| 4 | [adv] over a period [prep] | 34 |
|
| 5 | [adv] over a period [prep] | 34 |
|
| 6 | [adv] for a period [prep] | 19 |
|
| 7 | [adv] for a period [prep] | 19 |
|
| 8 | [adv] after a period [prep] | 14 |
|
| 9 | [adv] after a period [prep] | 14 |
|
| 10 | [adv] in a period [prep] | 10 |
|
| 11 | [adv] in a period [prep] | 10 |
|
| 12 | gradually [prep] a period [prep] | 7 |
|
| 13 | only [prep] a period [prep] | 5 |
|
